Drive mechanism for an injection device

ABSTRACT

The disclosure relates to an injection device for expelling of a number of preset or user-selectable doses of a medicament. The injection device includes an elongated housing extending along an axial direction and configured to accommodate a cartridge containing the medicament and having a bung sealing a proximal end of the cartridge, a windup expelling mechanism, and a dose setting mechanism. The dose setting mechanism includes a handle , a dose tracking member, and a limiter. The dose tracking member is rotatable relative to the housing within a range of positional states and operatively connectable to the handle for tracking a rotation thereof. The limiter is operationally engageable with the dose tracking member and a trigger of the windup expelling mechanism for blocking actuation of the trigger when the dose tracking member is in one of a number of predetermined sections of the range of positional states.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/636,267, filed Feb. 3, 2020, which is the national stageentry of International Patent Application No. PCT/EP2018/053740, filedon Feb. 15, 2018, and claims priority to Application No. EP 17305172.3,filed on Feb. 16, 2017, the disclosures of which are incorporated hereinby reference.

TECHNICAL FIELD

The disclosure relates to one aspect of an injection device, such like apen-type injector for expelling of preset or user-selectable doses of amedicament. In particular, the disclosure relates to an injection devicecomprising a windup expelling mechanism and comprising a dose settingmechanism, wherein the dose setting mechanism is configured to impede orto block a dose expelling procedure when the dose actually set does notmatch a predefined or prescribed dose size.

BACKGROUND

Injection devices for setting and dispensing a single or multiple dosesof a liquid medicament are as such well-known in the art. Generally,such devices have substantially a similar purpose as that of an ordinarysyringe.

Injection devices, in particular pen-type injectors have to meet anumber of user-specific requirements. For instance, with patient'ssuffering chronic diseases, such like diabetes, the patient may bephysically infirm and may also have impaired vision. Suitable injectiondevices especially intended for home medication therefore need to berobust in construction and should be easy to use. Furthermore,manipulation and general handling of the device and its componentsshould be intelligible and easily understandable. Moreover, a dosesetting as well as a dose dispensing procedure must be easy to operateand has to be unambiguous.

Typically, such devices comprise a housing including a particularcartridge holder, adapted to receive a cartridge at least partiallyfilled with the medicament to be dispensed. Such devices furthercomprise a drive mechanism or expelling mechanism, usually having adisplaceable piston rod which is adapted to operably engage with apiston of the cartridge. By means of the drive mechanism and its pistonrod, the piston of the cartridge is displaceable in a distal directionor dispensing direction and may therefore expel a predefined amount ofthe medicament via a piercing assembly, which is to be releasablycoupled with a distal end section of the housing of the injectiondevice.

The medicament to be dispensed by the injection device is provided andcontained in a multi-dose cartridge. Such cartridges typically comprisea vitreous barrel sealed in a distal direction by means of a pierceableseal and being further sealed in proximal direction by the piston. Withreusable injection devices an empty cartridge is replaceable by a newone. In contrast to that, injection devices of disposable type are to bediscarded when the medicament in the cartridge has been dispensed orused-up.

For some applications it can be advantageous to limit the minimummedicament dose that can be delivered from a device as well as themaximum dose. This may, for example, ensure that only a therapeuticallyeffective dose can be administered. Such a functionality may beparticularly relevant to combinations of drugs, where a minimum quantityof the combined drug is required to ensure sufficient delivery of oneelement of the combination to be therapeutically effective, whilstallowing some variation of the dose, which may be important for theother element of the combination.

In some applications it may be advantageous to offer a device whichallows delivery of only one fixed dose value but also permits a‘priming’ operation to be undertaken before each dose is administered.

A further application could be for a therapy in which a range ofdiscrete, non-sequential doses of a medication may be required. Forexample the range of doses may be needed to satisfy the therapeuticneeds of different user groups, or to allow individual users to delivera different dose at different times of the day e.g. in the morning or inthe evening.

It is therefore desirable to have an injection device that provides alimitation of deliverable dose values to a limited number of generallyavailable dose values. The injection device should allow delivery ofonly one or several fixed dose values. The injection device should beconfigured to prevent setting or expelling of doses that do not matchwith a pre-described or predefined dose size.

SUMMARY

In one aspect an injection device is provided for expelling of a numberof preset or user-selectable doses of a medicament, the injection devicecomprises:

-   -   an elongated housing extending along an axial direction (z) and        configured to accommodate a cartridge containing the medicament        and having a bung sealing a proximal end of the cartridge,    -   a windup expelling mechanism comprising a piston rod, a        mechanical energy reservoir and a trigger, wherein the trigger        is movable between an idle position (i) and a dose expelling        position (d) relative to the housing and configured to, when        moved into the dose expelling position (d), release energy from        the mechanical energy reservoir to the piston rod thereby        axially driving the piston rod relative to the housing in order        to urge against the bung,    -   a dose setting mechanism comprising a handle for rotationally        selecting a dose and/or for arming the windup expelling        mechanism, a dose tracking member and a limiter, wherein the        dose tracking member is rotatable relative to the housing within        a range of positional states and operatively connectable to the        handle for tracking a rotation thereof, and wherein the limiter        is operationally engageable with the dose tracking member and        the trigger for blocking actuation of the trigger when the dose        tracking member is in one of a number of predetermined sections        of the range of positional states.

The windup expelling mechanism provides mechanical energy to drive andto move the piston rod in a distal axial direction, i.e. towards adispensing end of the injection device. By means of the triggermechanical energy stored in the mechanical energy reservoir isreleasable. By means of one or several clutches the mechanical energy istransferable into a driving momentum or driving force acting on thepiston rod for driving the same in distal direction relative to thehousing. The trigger may be operably connected to one or severalclutches of the windup expelling mechanism and/or of the dose settingmechanism in order to release a distally directed motion of the pistonrod under the effect of a depleting mechanical energy reservoir.

The dose tracking member is typically located inside the housing. It isrotatable relative to the housing. It may comprise a cylindricalgeometry and may be completely arranged inside the housing. The dosetracking member may be selectively engageable with the handle, typicallyat least during dose setting, i.e. when the injection device is in adose setting mode. The dose tracking member may be axially fixed to thehousing. Alternatively, the dose tracking member may be rotationally andtranslationally coupled to the housing. The dose tracking member and thehousing may be threadedly engaged. A position or orientation of the dosetracking member relative to the housing is directly correlated to thesize of a dose actually set. Typically, the dose tracking member isdisplaceable between a zero dose configuration, in which the size of thedose set by the dose setting mechanism equals zero and a maximum doseconfiguration, in which the size of the dose set by the dose settingmechanism is at a maximum.

The dose tracking member is continuously displaceable relative to thehousing. The magnitude of a displacement of the dose tracking member incomparison to the zero dose configuration is directly proportional tothe size of the dose actually set. Any variation of the orientation orposition of the dose tracking member relative to the housing iscorrelated to a respective variation of the size of a dose actually set.

The limiter is operationally engageable with the dose tracking memberfor blocking actuation of the trigger. The trigger may be selectively orpermanently operationally engaged with the limiter. The trigger and thelimiter may be arrangeable in an abutment configuration. The abutmentconfiguration may coincide with the idle position (i) or with the doseexpelling position (d). The abutment configuration may be also locatedthere between. When in the abutment configuration the trigger may beaxially engaged with the limiter. A further axial displacement of thetrigger, e.g. in a distal direction, and beyond the abutmentconfiguration is only possible when the limiter is allowed to moverelative to the dose tracking member.

A longitudinal or axial movement or translational displacement of thelimiter relative to the dose tracking member is blocked when the dosetracking member is in one of a number of predetermined sections of therange of possible positional states. The respective movement is onlyallowed if the dose tracking member is located outside the number ofpredetermined sections of the range of possible positional states. Inthe present context the term “positional states” refers to the positionand/or the orientation of the dose tracking member. If the dose trackingmember is outside the predetermined sections of the range of possiblepositional states the mutual interaction of the dose tracking member andthe limiter is such that the limiter is hindered to be displaced or tobe moved relative to the dose tracking member. In this way and due to anabutment configuration between the limiter and the trigger a furtherdisplacement of the trigger towards the dose expelling position iseffectively blocked and impeded.

In this case an actuation force acting on the trigger and being largeenough to displace the trigger from the idle position towards and intothe dose expelling position is counteracted by the abutment of thetrigger with the limiter and further through the engagement of thelimiter with the dose tracking member. Typically, the dose trackingmember is axially fixed in a selected positional state. The limiter maybe in axial abutment with the dose tracking member at least towards adistally directed displacement relative to the dose tracking member.Furthermore the trigger may be in axial abutment with the limiter. Inthis way a distally directed dispensing force acting on the trigger iscounteracted by the axial engagement of the housing with the dosetracking member, the axial engagement of the dose tracking member withthe limiter and the axial engagement of the limiter with the trigger. Ineffect and when in a blocking configuration, the interaction of the dosetracking member with the limiter and with the trigger impedes anactuation of the trigger towards the dose expelling position.Consequently, a dispensing action or an expelling procedure cannot betriggered or initiated.

In one example the operational engagement between the dose trackingmember and the limiter comprises a first pair of keying features and asecond pair of keying features that are located on the limiter and onthe dose tracking member.

One pair of keying features comprises at least a first keying featureand a second keying feature. The first keying feature is located on thedose tracking member and the second keying feature is located on thelimiter the first keying feature and the second keying featureconstitute a pair of keying features. The first and the second keyingfeatures of a pair of keying features comprise complementary shapes andmutually corresponding geometries. The first keying feature and thesecond keying feature are configured such that a displacement ormovement of the limiter relative to the dose tracking member is onlypossible when the first keying feature matches and aligns with thesecond keying feature of a pair of keying features. In all otherpositional states in which the first and the second keying features donot match or in which the first and second keying features are notproperly aligned a movement of the limiter relative to the dose trackingmember, typically a distally and axially directed movement of thelimiter relative to the dose tracking member, is effectively impeded.

There is provided also a second pair of keying features also having afirst keying feature and a second keying feature, wherein the firstkeying feature is located on the dose tracking member and wherein thesecond keying feature is located on the limiter. Likewise the first pairof keying features also the keying features of the second pair of keyingfeatures comprise complementary shapes and mutually correspondinggeometries. The first keying feature and the second keying feature ofthe second pair of keying features are also configured such that adisplacement or movement of the limiter relative to the dose trackingmember is only possible when the first keying feature matches and alignswith the second keying feature of the second pair of keying features.

To achieve a blocking of the trigger and/or of the limiter it isgenerally sufficient when the keying features of only one pair of thefirst and second pair of keying features mutually engage.

In one embodiment the keying features of the first pair of keyingfeatures and the keying features of the second pair of keying featuresare configured such that the first pair of keying features and thesecond pair of keying features simultaneously engage or simultaneouslydisengage. Hence, when the keying features of the first pair of keyingfeatures are engaged so as to block or to impede actuation of thetrigger or displacement of the limiter also the keying features of thesecond pair of keying features will be engaged. In this way, the firstpair of keying features and the second pair of keying featuressimultaneously provide a multiple abutment configuration or blockingconfiguration. Any forces or counterforces between the limiter and thedose tracking member can be distributed among the first pair of keyingfeatures and the second pair of keying features. In effect, maximumforces or a force effect present to individual keying features of thefirst or second pair of keying features can be reduced in this way. Thisallows and supports a miniaturized and intricate design of the keyingfeatures because a maximum force effect or a maximum load that may beapplied via the trigger and the limiter is distributed among theplurality of available keying features.

The injection device is not generally limited to only a first pair ofkeying features and a second pair of keying features. There may beprovided also a third pair of keying features or even more pairs ofkeying features.

In another example the dose tracking member is engaged with the housingby a slotted link arranged along a cylindrical surface, and wherein themovement of the dose tracking member includes a rotation around a longaxis (z) of the cylindrical surface.

The slotted link may provide a combined translational and rotationaldisplacement of the dose tracking member relative to the housing. Theslotted link may comprise a helical shape. The slotted link may beformed between an outside facing sidewall portion of the dose trackingmember and an inside facing sidewall portion of the housing. The dosetracking member may comprise a cylindrical shape and the housing maycomprise a cylindrical shape. An outer diameter of the dose trackingmember may be smaller than an inner diameter of the housing. The dosetracking member may be completely accommodated inside the housing. Thecylindrical surface of the slotted link may be provided on the outsideof the dose tracking member and/or on the inside of the housing.Typically, the slotted link is provided on the inside of the housing,which is cylindrically shaped. The dose tracking member may alsocomprise a cylindrical structure. It may comprise a shell structure oran annular structure to fit into the housing. The long axis of thecylindrical surface may coincide with a longitudinal axis of theelongated housing.

In another example the operational engagement between the dose trackingmember and the limiter comprises one or more elongated keyingstructures, wherein each of the keying structures being arranged inparallel or being formed integrally with the slotted link between thedose tracking member and the housing.

The elongated keying structure on the dose tracking member is configuredto define those positional states of the dose tracking member in whichexpelling of a dose of the medicament is allowable and supported. Theremay be provided at least one elongated keying structure between the dosetracking member and the limiter. The elongated keying structure may beprovided on an outside facing sidewall portion of the dose trackingmember. It may be also provided on an inside of the dose trackingmember. The elongated keying structure may be characterized by at leastone keying feature. The keying feature may comprise an interruption ofthe elongated keying structure or may comprise a recess in the elongatedkeying structure.

When having two or more elongated keying structures for instance on thedose tracking member each of the two or more elongated keying structuresextends parallel to the other of the elongated keying structures of thedose tracking member. In a similar manner the elongated keyingstructures may be also provided on the limiter. Typically, one of thedose tracking member and the limiter comprises an elongated keyingstructure to operationally engage with a keying feature of the other oneof the dose tracking member and the limiter.

The keying structure of one of the dose tracking member and the limiterand a keying feature of the other one of the dose tracking member andthe limiter may form or may constitute at least one of the pair ofkeying features.

The elongated keying structures may be integrally formed with theslotted link that is provided between the dose tracking member and thehousing. In one embodiment the elongated keying structure comprises ahelically wound thread on an outside facing sidewall portion of the dosetracking member. The helically wound thread may comprise a doublefunction. A portion thereof may be in threaded engagement with acorrespondingly shaped threaded section on an inside facing sidewallportion of the housing. Another portion thereof may form or maycontribute to the pair of keying features between the dose trackingmember and the limiter. When implemented on or with the dose trackingmember the elongated keying structures provide a well-defined threadedengagement between the dose tracking member and the housing. Theyfurther provide at least two keying features of two pairs of keyingfeatures to engage with the limiter.

In another example the rotation of the dose tracking member includes atranslation along the axis (z) of the cylindrical surface. The slottedlink may be configured as a helically wound thread between the dosetracking member and the housing. Correspondingly and in accordance withthe pitch of the thread, a rotation of the dose tracking member relativeto the housing always comes along with a longitudinal movement ortranslation thereof along the long axis of the cylindrical surface,hence along the axial direction as defined by the elongated housing.

In another example the slotted link comprises a continuously woundthread. The continuously wound thread may be provided on one of the dosetracking member and the housing. If the continuously wound slotted linkis provided on an inside facing sidewall portion of the housing it issufficient when the dose tracking member comprises a threaded section onan outside facing sidewall portion that may be intersected orinterrupted. In an alternative the continuously wound thread may beprovided on an outside facing sidewall portion of the dose trackingmember. It would then be sufficient when the inside facing sidewallportion of the housing only comprises a threaded section of limitedsize.

Having a continuously wound thread on the inside facing sidewall portionof the housing enables to implement and interrupted or recessed threadedsection on the outside facing sidewall portion of the dose trackingmember. Recesses or interruptions in the threaded section of the dosetracking member may provide a keying feature to engage with acorrespondingly shaped keying feature of the limiter.

In another example the limiter is arranged for actuation coaxially withthe axis (z) of the cylindrical surface. The limiter may be rotationallyfixed or rotationally secured to the housing. It may be axiallydisplaceable relative to the housing between a blocking position (b) anda release position (r). The blocking position may coincide with aproximal end position. The release position may coincide with a distalend position of the limiter. If the dose tracking member is an allowablepositional state the keying features of the dose tracking member and thelimiter mutually match and the limiter is movable from the proximallocking position towards the distal release position. In other, hence,non-allowable positional states of the dose tracking member the limiteris effectively hindered or impeded to be moved from the proximalblocking position towards the distal release position. Since the limitermay be in axial abutment with the trigger a respective axialdisplacement of the trigger is blocked or impeded accordingly.

In another example the handle is operatively connectable to themechanical energy reservoir for harvesting energy from rotationalactuation of the handle and for arming the mechanical energy reservoir.

The handle may provide a double function. In one aspect it may providesetting of a user selectable dose. In another aspect it may beconfigured for arming the windup expelling mechanism. Setting of a doseby actuating or moving the handle relative to the housing in a doseincrementing fashion may increase the energy level stored by themechanical energy reservoir. The handle may be selectively connectableto the mechanical energy reservoir at least during dose setting, i.e.when the dose setting mechanism and/or the windup expelling mechanism isin a dose setting mode. When operably connected or coupled to themechanical energy reservoir actuation or movement of the handle may actagainst a restoring force provided by the mechanical energy reservoir.The mechanical energy reservoir may be configured as a spring or maycomprise a spring, e.g. a torsion spring or a helically wound spring.

In another example the limiter is axially connected to the trigger fortransferring axial-translational forces from the limiter to the trigger.

The limiter may be permanently fixed to the trigger and vice versa sothat any movement or axial translation of the trigger equally transfersinto a corresponding movement or axial translation of the limiter. Inanother example the trigger may be axially displaceable relative to thehousing against the action of a trigger spring. In the idle position thetrigger may be separated from the limiter. It may be only due to andduring an axially directed movement or displacement of the trigger thatthe trigger gets in axial abutment with the limiter. The trigger maythen be in an abutment configuration with the limiter. In the abutmentconfiguration the trigger may be located axially between the idleposition and the dose expelling position. A further axial displacementof the trigger towards the expelling position may then slave the limiterand may displace the limiter accordingly in axial direction, e.g. inaxial distal direction. The limiter and the trigger may comprisemutually corresponding fastening elements by way of which the limiter isdisplaceable from the release position towards the blocking position. Aproximally directed displacement of the limiter from the releaseposition towards the initial blocking position may be conducted by thetrigger and by the trigger spring.

In another example the trigger is axially displaceable relative to thehousing, wherein the limiter is axially engageable with the trigger andwherein the limiter has a first engaging section and a second engagingsection, wherein the first engaging section is circumferentially offsetfrom the second engaging section.

In another example the at least one keying feature of the first pair ofkeying features is located on the first engaging section and wherein atleast one keying feature of the second pair of keying features islocated on the second engaging section. The keying features of the twopairs of keying features that are located on the limiter may beexclusively located and provided on the first and the second engagingsections of the limiter, respectively. Since the first and secondengaging sections are tangentially or circumferentially offset they aremechanically engaged with keying features of the first and second pairof keying features that are located on the dose tracking member. Thekeying features on the dose tracking member will be arranged at acorresponding circumferential offset. When the first pair of keyingfeatures and the second pair of keying features simultaneously engage ina blocking configuration the circumferential offset of the first pair ofkeying features and of the second pair of keying features effectivelyprevents a tilting or canting of the limiter relative to the dosetracking member and relative to the housing. By means of at least twopairs of keying features that are arranged at a circumferential offsetany axially directed force effect provided to the trigger and to thelimiter accordingly can be counteracted in a more balanced way.

In another example at least one of the first engaging section and thesecond engaging section is configured to engage with one of theelongated keying structures on the dose tracking member to impedemovement of the trigger towards the dose expelling position (d).Typically, the keying features provided on the first and on the secondengaging sections engage with the correspondingly shaped elongatedkeying structures on the dose tracking member. The keying features andthe keying structures are configured such that they simultaneouslyengage or simultaneously disengage in order to provide an at leasttwofold blocking in cases where the positional states of the dosetracking member corresponds to a non-allowed dose size.

In another example the one or more elongated keying structures compriseat least one of a first outer thread and a second outer thread on anoutside surface of the dose tracking member.

As an example, there may be provided a first outer thread and a secondouter thread on the outside surface of the dose tracking member. Atleast one of the first and second outer threads may be threadedlyengaged with the slotted link or with an inner threaded section of thehousing. At least one of the first and second outer threads may providea keying feature of at least one of the first and second pairs of keyingfeatures to engage with a correspondingly shaped keying feature on atleast one of the first and second engaging sections.

The first and the second outer thread may be arranged intertwined. Thefirst and the second outer thread may be arranged in a nestedconfiguration, hence in an axially overlapping configuration. In someexamples, the first and the second outer thread are completely axiallyseparated. There, one of the first and second outer threads may beprovided at a distal section of the dose tracking member whereas anotherone of the first and second outer threads may be provided at a proximalportion of the dose tracking member. The distal portion and the proximalportion of the dose tracking member may be non-overlapping.

With another example the keying features of at least one of the firstengaging section and the second engaging section comprise a radiallyinwardly extending protrusion. Typically, at least one of the firstengaging section and the second engaging sections is configured toengage with at least one of the first outer thread and the second outerthread.

It is conceivable that the first engaging section and the secondengaging section both comprise at least one radially inwardly extendingprotrusion, wherein at least one of the protrusions is engaged with atleast one of the first outer thread and the second outer thread.Typically, the first and the second protrusions may be in engagementwith the first and with the second outer thread, respectively. Whenhaving a first and a second radially inwardly extending protrusion thefirst and the second engaging sections can be located radially outsidethe dose tracking member. The axial extension of the protrusions issmaller than the axial distance between two neighboring threadedstructures of the first and the second outer thread. In this way theprotrusions can be permanently engaged with the first and the secondouter thread.

In another example the first outer thread and the second outer threadhave the same thread pitch and wherein the first engaging section isengageable with the first outer thread and wherein the second engagingsection is engageable with the second outer thread. Typically, the firstprotrusion is engaged with the first thread. Simultaneously, the secondprotrusion is engaged with the second thread. First and secondprotrusions are typically arranged circumferentially offset. They may behence arranged at a predefined tangential distance from each other. Whenarranged circumferentially offset and when simultaneously engaged withthe first outer thread and the second outer thread the first and thesecond engaging sections provide a distribution of mechanical load thatis present on the limiter. A tilting or canting of the limiter relativeto the dose tracking member can be prevented in this way. Moreover, themechanical engagement and the reliability of an axial force transferfrom the trigger to the limiter and further to the dose tracking membercan be improved. Since the first and the second outer thread comprise anidentical thread pitch the first and the second protrusions remain in athreaded or mechanical engagement with the first and with the secondthread, respectively, even when the dose tracking member is subject to arotational movement relative to the limiter.

In another example the second outer thread is located at a predefinedaxial offset from the first outer thread and wherein the axial offset islarger than or equal to an axial distance between the idle position andthe dose dispensing position of the trigger. By arranging the first andthe second outer thread at a predefined axial offset the first and thesecond outer thread may be individually encoded. For instance, the firstand the second outer thread may be provided with at least one or severalrecesses that allow and support an axial movement of keying features ofthe limiter axially through and beyond the respective thread. Apredefined axial distance between the first outer thread and a secondouter thread enables at least a limited axial displacement of thelimiter relative to the dose tracking member when the keying features ofthe dose tracking member are aligned with the keying features of thelimiter. This limited axial displacement may be sufficient to switch thedose setting mechanism and/or the windup expelling mechanism from thedose setting mode into the dose dispensing mode and hence to support andto enable a triggering of a dose expelling procedure.

The keying features of the dose tracking member and the limiter may beconfigured such that the first pair of keying features and the secondpair of keying features simultaneously align so as to enable an axialdisplacement of the limiter relative to the dose tracking member.Otherwise and if one pair of keying features is out of alignment alsothe other pair of keying features will be out of alignment. In such aconfiguration the keying features of the limiter will be in engagementwith the keying structures of the dose tracking member. For instance,the protrusions of the first and the second engaging section are inmechanical engagement and hence in axial abutment with the first and thesecond outer thread of the dose tracking member.

In another example the second outer thread is located at a predefinedradial offset from the first outer thread. Instead of an axialseparation of first and second outer thread it is even conceivable thatthe first and the second outer thread axially overlap. Here, the firstouter thread may comprise a first radially outwardly extending dimensionand the second outer thread may comprise a second radially outwardlyextending dimension. The second dimension may be larger than the firstdimension. Accordingly, correspondingly shaped first and secondprotrusions of the first and second engaging sections may comprisedifferently sized radially inwardly extending dimensions. When the firstprotrusion is configured to engage with the first outer thread and whenthe second protrusion is configured to engage with the second outerthread the radially inwardly directed extension of the second protrusionmay be shorter than the radially inwardly directed extension of thefirst protrusion. In this way, the first and second thread may beindividually encoded or may be provided individually with recessesthrough which the first and the second protrusions may pass through inthe axial direction, respectively.

In another example the at least one of the first outer thread and thesecond outer thread is discontinuous and comprises at least a firstrecess, wherein the first recess is shaped to receive the protrusionand/or wherein the protrusion is axially displaceable through the firstrecess. The tangential or circumferential extension of the first recessis at least as large as a corresponding tangential or circumferentialextension of the at least one protrusion of the first engaging sectionor second engaging section. In this way the at least one protrusion canaxially slide through the recess. The at least one protrusion mayaxially pass by or may pass through the respective outer recess.

Typically, the first outer thread and the second outer thread eachcomprise at least a first recess configured to receive the firstprotrusion and to receive the second protrusion of the first engagingsection and the second engaging section, respectively. If the dosetracking member is in an allowable positional state, i.e in a state inwhich a dose dispensing or dose expelling action is allowed andsupported by the injection device, the first protrusion will be alignedwith a recess of the first outer thread and the second protrusion willbe aligned with a recess in the second outer thread. In thisconfiguration the limiter is axially displaceable relative to the dosetracking member. The first protrusion may slide through the at least onerecess of the first outer thread and the second protrusion maysimultaneously pass through the at least one recess of the second outerthread.

Typically, the at least one recess of the first outer thread and the atleast one recess of the second outer thread are arranged at a predefinedcircumferential offset. The circumferential offset between the recess ofthe first outer thread and the at least one recess of the second outerthread is substantially identical to the circumferential of said of thefirst keying feature and the second keying feature of the limiter. Inother words the circumferential offset between the recesses is identicalor corresponds to the circumferential offset of the first protrusion andthe second protrusion that are provided on the first engaging sectionand the second engaging section of the limiter.

In another example the slotted link comprises an inner threaded sectionon the housing and comprises at least one of the first outer thread andthe second outer thread on the dose tracking member. Here, at least oneof the first outer thread and the second outer thread fulfills a doublefunction. The respective outer thread is not only configured to providean axial abutment for the limiter but also serves to provide a threadedengagement between the dose tracking member and the housing of theinjection device. With some examples, the inner threaded section on theinside facing sidewall of the housing is located axially offset and at apredefined axial distance from the keying features of the limiter. Thehousing may therefore comprise an axially extending slot or recess on aninside facing sidewall to slidably support the limiter. The slot orrecess can be located at a predefined axial distance from the innerthreaded section. In this way there can be provided sufficient space foran axially slidable displacement of the limiter inside the housing.

In another example:

-   -   the inner threaded section is located axially adjacent to at        least one of the first engaging section and the second engaging        section, or    -   the inner threaded section axially overlaps with at least one of        the first engaging section and the second engaging section,        wherein the inner threaded section is arranged tangentially        adjacent to at least one of the first engaging section and the        second engaging section of the limiter.

With this example the inner threaded section comprises a circumferentialor tangential extension that is shorter than 180° or shorter than 120°or shorter than 80° of the total circumference of the housing, which istypically cylindrically shaped and comprises a circular cross-section.There may be provided two or more inner threaded sections on an insidefacing sidewall of the housing to engage with at least one of the firstand the second outer thread. It is conceivable to have a first innerthreaded section located circumferentially between the first and thesecond engaging sections of the limiter and to have a second innerthreaded section located circumferentially between the first and thesecond engaging sections of the limiter.

The first and the second threaded sections may be threadedly engagedwith the first outer thread of the dose tracking member. Alternatively,they may be threadedly engaged with the second outer thread of the dosetracking member. It is also conceivable that the first inner threadedsection is threadedly engaged with the first outer thread and that thesecond inner threaded section is threadedly engaged with the secondouter thread. A multiple threaded engagement of the dose tracking memberand the housing provides a reliable and secure arrangement of the dosetracking member inside the housing that is substantially free ofbacklash, canting or tilting.

Moreover, with an axially overlapping configuration of the firstengaging section and the threaded engaging section with the innerthreaded section the total axial elongation of the injection device canbe reduced. In effect a compact design of the injection device can beprovided.

In another example the limiter comprises a proximal end section toengage with the trigger and wherein the limiter is axially displaceablerelative to the housing between a proximal blocking position and adistal release position. Typically, the limiter is axially slidablydisplaceable relative to the housing. Hence, the trigger is transferablefrom the proximal blocking position to the distal release position byway of a sliding motion relative to the housing. Typically, the limiteris located inside the housing. It is displaceable from the blockingposition towards the release position by means of the trigger.

The limiter may comprise an annular shape at a proximal end section. Bymeans of an annular shaped proximal end forces transferred from thetrigger towards and into the limiter in the distal direction may bereceived and can be evenly distributed among the first and the secondengaging sections of the dose tracking member. The proximal end of thelimiter may be shaped to correspond to a shape of a distal end of thetrigger. Both, the trigger and the limiter may have an annular abutmentsection so as to evenly transfer any distally directed force effect fromthe trigger towards the limiter. In this way any tilting motion or cantof the limiter can be effectively prevented.

In another example the limiter comprises a first axially extending legand a second axially extending leg, wherein the first leg comprises orforms the first engaging section and wherein the second leg comprises orforms the second engaging section. The first leg and the second leg mayextend parallel with respect to each other. They may be arranged atdiametrically opposite locations on the outer circumference of the dosetracking member. It is conceivable that the limiter comprises three ormore legs extending parallel in the axial direction from a proximal endsection of the limiter towards the distal direction.

The keying features of the limiter may be provided at a distal endsection of the legs. Hence, radially inwardly extending protrusions ofthe keying features may be provided at a free end of the first and thesecond legs, respectively. In radial direction the legs may besandwiched between an inside facing portion of the sidewall and theouter circumference of the dose tracking member. The radial thickness ofthe legs is dimensioned so as to fit between an inside facing sidewallportion of the housing and the at least first or second outer thread onthe dose tracking member. In this way a radial deformation or radialmovement of the keying features of the dose tracking member can beeffectively limited. The keying features of the limiter may thereforeremain in permanent mechanical engagement with the keying structure onthe outer circumference of the dose tracking member.

In another example the first leg and the second leg are resilientlydeflectable in a radial direction and wherein the first leg and thesecond leg each comprise a radially and axially extending beveledsection at a radially outwardly facing side to engage with acomplementary shaped counterpart section of the trigger. With thisexample the mutually corresponding keying features of the limiter andthe dose tracking member are configured for a radial displacement. Ifthe dose tracking member is in an allowable positional state in whichdose dispensing or dose expelling is supported the keying features ofthe limiter may be radially displaceable relative to the dose trackingmember.

For this, the dose tracking member may comprise radially extendingrecesses on its outer circumference. The radially extending recesses maybe also provided in at least one of the first and the second outerthreads. A radially inwardly directed deflection of the keying featuresof the limiter is only allowed and possible if the keying features ofthe limiter are correctly aligned with correspondingly shaped keyingfeatures of the dose tracking member. Then and in response to an axiallydirected displacement of the trigger the engaging sections of thelimiter will be subject to a radially inwardly directed displacement. Inthis way, the engaging sections of the limiter will give way to thetrigger and may support and allow a distally directed displacement ofthe trigger relative to the limiter.

Otherwise and if the dose tracking member is in a non-supported ornon-allowed positional state, the keying features of the limiter and thedose tracking member are out of alignment and a radially inwardlydirected displacement of the keying features of the limiter iseffectively prevented, e.g. by a radial abutment of the keying featuresof the limiter by the keying structure of the dose tracking member. Itis then that the beveled section of the limiter is and remains in axialabutment with the complementary shaped beveled section of the trigger.If the beveled section of the limiter is hindered to deflect radiallyinwardly by means of the radial abutment between the respective engagingsection or leg of the limiter with an outer circumference or keyingstructure of the dose tracking member a distally directed displacementof the trigger is effectively blocked.

In another example a radially inwardly directed deflection of at leastone of the first leg and the second leg in response to a distallydirected displacement of the trigger is impeded as long as at least oneprotrusion of the first leg and the second leg is engaged with at leastone of the first thread and the second thread. A radially inwardlydirected deflection of at least one of the first and the second legs issupported and allowed as soon as the respective keying feature of thelimiter is aligned with the corresponding keying feature of the dosetracking member.

Typically, the first and the second keying features of the limitersimultaneously align with correspondingly shaped keying features of thedose tracking member. The beveled section of the first leg and of thesecond leg of the first and the second engaging sections of the limiterare both in abutment or engagement with the correspondingly shapedbeveled section of the trigger. A distally directed depression of thetrigger from the idle position towards the dose dispensing position thenleads to a radially inward deflection or movement of the engagingsection and hence of the legs of the limiter. Due to this radiallyinwardly directed movement or deflection the trigger can be displacedfrom the idle position towards the dose expelling position and theprocess of dose expelling can be triggered.

In another example there is further provided a number sleeve comprisinga helical shaped sequence of dose indicating numbers on its outercircumference and wherein the dose tracking member is configured as thenumber sleeve or wherein the dose tracking member comprises a threadedtracking sleeve rotationally locked and axially displaceably engagedwith the number sleeve. By configuring the dose tracking member as thenumber sleeve the total number of components of the dose settingmechanism or of the windup expelling mechanism can be reduced. Thisenables a further miniaturization of the injection device. Moreover,costs for production and assembly of the injection device can be reducedin this way.

When implemented as a number sleeve and when having a first and a secondouter thread the pitch of the first and the second outer threads may besufficiently large so that consecutive numbers are arranged along ahelical structure extending between adjacent convolutions of the firstand the second outer thread. As seen in an axial direction the firstthread may be followed by the second thread. The threads may beseparated at a predefined axial offset “0”. Then there may follow adisplay portion that is provided with dose indicating numbers. Furtherin axial direction there will follow the next convolution of the firstthread. In some configurations the axial extension or the axial heightof the display portion is larger than the axial offset between the firstand the second outer thread. This implies a comparatively large threadpitch of the first and the second outer thread. In some configurationsthe axial extension of the display portion is at least twice as large asthe axial offset between the first and the second outer thread.

In another example the keying features of the limiter comprise a anangled or beveled edge complementary shaped to a chamfered end sectionof at least one of the keying structures of the dose tracking member andwherein the limiter is axially displaceable towards a blocking positionthrough engagement with the chamfered end section. With this example thelimiter may be moved axially as a result of a rotational motion of thedose tracking member. In an initial configuration the keying features ofthe limiter may be arranged in an at least partially overlappingconfiguration with the chamfered section of the keying structures of thedose tracking member.

When the dose tracking member is subject to a rotation, e.g. during adose setting procedure the beveled edge of the keying features mayengage and may slide along the chamfered end section of the at least onekeying structure of the dose tracking member. Consequently, the keyingfeature of the limiter and hence the entire limiter may become subjectto an axial displacement towards and into a a blocking position as thedose tracking member is rotated and as long as the dose tracking memberis in one of a number of predetermined sections of the range ofpositional states, in which a dose dispensing or dose expelling actionis effectively blocked.

The axial displacement of the limiter may then lead to a blocking of thetrigger. Here, it is conceivable that a proximal end section of thelimiter engages at least one blocking member that is e.g. pivotable ormovable relative to the housing. The axial displacement of the limitermay lead to a movement or pivoting motion of the blocking member. Whenarriving in a blocking position the blocking member may effectivelyprevent a depression or actuation of the trigger.

With this example it may be of particular benefit that any force effectapplied to the trigger is only and exclusively transferred to theblocking member, which may be pivotably or movably connected to thehousing. In this way any counterforces to prevent actuation of thetrigger are provided or supported by the housing. The dose trackingmember and the limiter are located outside a flux of force or outside ofa load path.

In another example the mechanical energy reservoir comprises a helicaldriving spring having a first end connected to the housing and having asecond end connected to the dose tracking member and wherein the dosetracking member is rotatable in a dose incrementing direction againstthe action of the driving spring. The helical driving spring may serveand provide the mechanical energy reservoir. Since the helical drivingspring is connected with oppositely located ends to the dose trackingmember and to the housing, respectively the helical driving spring maybe tensed or biased during dose setting, i.e. when the dose trackingmember is subject to a rotation relative to the housing in a doseincrementing direction. In this way mechanical energy stored in thehelical driving spring is increased during the dose setting procedure.During a dose dispensing procedure the previously stored mechanicalenergy can be released from the helical driving spring. The dosetracking member may then be subject to a rotation in a dose decrementingdirection. The helical driving spring may be pretensed. In an initialconfiguration, i.e. in the zero dose configuration the helical springmay be preloaded with a predefined amount of mechanical energy. In thisway it is guaranteed that the mechanical energy stored in the helicaldriving spring is sufficient to conduct a dose dispensing procedure andto drive the piston rod in a distal direction during the dose dispensingor dose expelling procedure.

In another example there is further provided a driver axiallydisplaceable between a dose setting position and a dose dispensingposition and wherein the handle is rotatable relative to the housing forsetting of a dose of the medicament, wherein when in the dose dispensingposition the driver is rotationally locked to the piston rod and isrotationally disengaged from the handle and wherein when in the dosesetting position, the driver is rotationally disengaged from the pistonrod and is rotationally locked to the handle.

The driver may be implemented as a drive sleeve. The driver may bepermanently rotationally connected to the dose tracking member. Themechanical energy reservoir, e.g. the helical driving spring may beconnected with its second end to the driver. In the dose expelling ordose dispensing mode the driver will the released to rotate in the dosedecrementing direction under the action of the driving spring.Typically, there is provided at least a first clutch between the handleand the driver. There may be provided a second clutch between the driverand the piston rod. In the dose setting mode the first clutch is closedso that a rotation of the handle equally transfers to a rotation of thedriver while the second clutch is open. In this way the driver can berotated relative to the housing and relative to the piston rod. In thedose setting mode the piston rod is stationary relative to the housing.

For switching the dose setting mechanism and/or the windup expellingmechanism from the dose setting mode into the dose dispensing or doseexpelling mode the first clutch is opened while the second clutch isclosed. Typically, the second clutch is closed and the driver isrotationally locked to the piston rod before the first clutch is openedor released. In this way it is guaranteed that mechanical energy storedin the mechanical energy reservoir does not dissipate in an uncontrolledway. In the dose dispensing mode the driver is rotated in the dosedecrementing direction under the action of the mechanical energyreservoir. At the same time the dose tracking member returns into itsinitial or zero dose position. Numbers of a number sleeve typicallyappearing in a window of the housing successively decrease during thedose dispensing or dose expelling procedure. At the same time the handleis disconnected from the driver and does not rotate.

In another example there is provided a cartridge filled with themedicament and arranged inside the housing. The cartridge typicallycomprises a tubular-shaped or cylindrical barrel. Near a distal ordispensing end the barrel comprises a narrowing shoulder portion. Thedistal end of the cartridge may comprise a pierceable seal, such as aseptum. The pierceable seal is penetrable by a double-tipped injectionneedle. The injection needle is typically releasably connectable to adispensing end of the housing of the injection device. The housing ofthe injection device may comprise a proximal housing component alsodenoted as main housing component. The housing may further comprise adistal housing component also denoted as cartridge holder. The cartridgeis typically accommodated in the cartridge holder. The windup expellingmechanism and the dose setting mechanism are typically accommodated inthe main housing component. With disposable injection devices the mainhousing component and the cartridge holder are unreleasably connected.With reusable injection devices the main housing component and thecartridge holder are detachably or releasably connected so as to enablea replacement of an empty cartridge.

In the present context a distal end or distal direction refers to thatend section of the injection device from which the liquid medicament isexpelled. The proximal end or proximal direction refers to that endsection of the injection device which is furthest away from biologicaltissue of a patient to be treated with the medicament. The injectiondevice is typically configured for administration of a liquidmedicament, such as insulin or heparin. The injection device istypically configured for self-medication. It is configured for operationby only one hand of a user. The trigger typically provided at theproximal end of the injection device is configured to be depressed by athumb of a user while residual fingers of the same hand may grip thehousing of the injection device.

The term “drug” or “medicament”, as used herein, means a pharmaceuticalformulation containing at least one pharmaceutically active compound,

wherein in one embodiment the pharmaceutically active compound has amolecular weight up to 1500 Da and/or is a peptide, a proteine, apolysaccharide, a vaccine, a DNA, a RNA, an enzyme, an antibody or afragment thereof, a hormone or an oligonucleotide, or a mixture of theabove-mentioned pharmaceutically active compound,

wherein in a further embodiment the pharmaceutically active compound isuseful for the treatment and/or prophylaxis of diabetes mellitus orcomplications associated with diabetes mellitus such as diabeticretinopathy, thromboembolism disorders such as deep vein or pulmonarythromboembolism, acute coronary syndrome (ACS), angina, myocardialinfarction, cancer, macular degeneration, inflammation, hay fever,atherosclerosis and/or rheumatoid arthritis,

wherein in a further embodiment the pharmaceutically active compoundcomprises at least one peptide for the treatment and/or prophylaxis ofdiabetes mellitus or complications associated with diabetes mellitussuch as diabetic retinopathy,

wherein in a further embodiment the pharmaceutically active compoundcomprises at least one human insulin or a human insulin analogue orderivative, glucagon-like peptide (GLP-1) or an analogue or derivativethereof, or exendin-3 or exendin-4 or an analogue or derivative ofexendin-3 or exendin-4.

Insulin analogues are for example Gly(A21), Arg(B31), Arg(B32) humaninsulin; Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) humaninsulin; Asp(B28) human insulin; human insulin, wherein proline inposition B28 is replaced by Asp, Lys, Leu, Val or Ala and wherein inposition B29 Lys may be replaced by Pro; Ala(B26) human insulin;Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) humaninsulin.

Insulin derivates are for example B29-N-myristoyl-des(B30) humaninsulin; B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl humaninsulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin;B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30 human insulin; B29-N-(N-palmitoyl-Y-glutamyl)-des(B30)human insulin; B29-N-(N-lithocholyl-Y-glutamyl)-des(B30) human insulin;B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin andB29-N-(ω-carboxyheptadecanoyl) human insulin.

Exendin-4 for example means Exendin-4(1-39), a peptide of the sequenceH-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.

Exendin-4 derivatives are for example selected from the following listof compounds:

H-(Lys)4-des Pro36, des Pro37 Exendin-4(1-39)-NH2,

H-(Lys)5-des Pro36, des Pro37 Exendin-4(1-39)-NH2,

des Pro36 Exendin-4(1-39),

des Pro36 [Asp28] Exendin-4(1-39),

des Pro36 [IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39); or

des Pro36 [Asp28] Exendin-4(1-39),

des Pro36 [IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),

des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39),

wherein the group -Lys6-NH2 may be bound to the C-terminus of theExendin-4 derivative;

or an Exendin-4 derivative of the sequence

des Pro36 Exendin-4(1-39)-Lys6-NH2 (AVE0010),

H-(Lys)6-des Pro36 [Asp28] Exendin-4(1-39)-Lys6-NH2,

des Asp28 Pro36, Pro37, Pro38Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro38 [Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,

H-des Asp28 Pro36, Pro37, Pro38 [Trp(O2)25] Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36 [Met(O)14, Asp28] Exendin-4(1-39)-Lys6-NH2,

des Met(O)14 Asp28 Pro36, Pro37, Pro38 Exendin-4(1-39)-NH2,

H-(Lys)6-desPro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Asn-(Glu)5 des Pro36, Pro37, Pro38 [Met(O)14, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-Lys6-des Pro36 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,

H-des Asp28 Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25]Exendin-4(1-39)-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-NH2,

des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2,

H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(S1-39)-(Lys)6-NH2,

H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]Exendin-4(1-39)-(Lys)6-NH2;

or a pharmaceutically acceptable salt or solvate of any one of theafore-mentioned Exendin-4 derivative.

Hormones are for example hypophysis hormones or hypothalamus hormones orregulatory active peptides and their antagonists as listed in RoteListe, ed. 2008, Chapter 50, such as Gonadotropine (Follitropin,Lutropin, Choriongonadotropin, Menotropin), Somatropine

(Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin,Leuprorelin, Buserelin, Nafarelin, Goserelin.

A polysaccharide is for example a glucosaminoglycane, a hyaluronic acid,a heparin, a low molecular weight heparin or an ultra low molecularweight heparin or a derivative thereof, or a sulphated, e.g. apoly-sulphated form of the above-mentioned polysaccharides, and/or apharmaceutically acceptable salt thereof. An example of apharmaceutically acceptable salt of a poly-sulphated low molecularweight heparin is enoxaparin sodium.

Antibodies are globular plasma proteins (˜150 kDa) that are also knownas immunoglobulins which share a basic structure. As they have sugarchains added to amino acid residues, they are glycoproteins. The basicfunctional unit of each antibody is an immunoglobulin (Ig) monomer(containing only one Ig unit); secreted antibodies can also be dimericwith two Ig units as with IgA, tetrameric with four Ig units liketeleost fish IgM, or pentameric with five Ig units, like mammalian IgM.

The Ig monomer is a “Y”-shaped molecule that consists of fourpolypeptide chains; two identical heavy chains and two identical lightchains connected by disulfide bonds between cysteine residues. Eachheavy chain is about 440 amino acids long; each light chain is about 220amino acids long. Heavy and light chains each contain intrachaindisulfide bonds which stabilize their folding. Each chain is composed ofstructural domains called Ig domains. These domains contain about 70-110amino acids and are classified into different categories (for example,variable or V, and constant or C) according to their size and function.They have a characteristic immunoglobulin fold in which two β sheetscreate a “sandwich” shape, held together by interactions betweenconserved cysteines and other charged amino acids.

There are five types of mammalian Ig heavy chain denoted by α, δ, ε, γ,and μ. The type of heavy chain present defines the isotype of antibody;these chains are found in IgA, IgD, IgE, IgG, and IgM antibodies,respectively.

Distinct heavy chains differ in size and composition; α and γ containapproximately 450 amino acids and δ approximately 500 amino acids, whileμ and ε have approximately 550 amino acids. Each heavy chain has tworegions, the constant region (C_(H)) and the variable region (V_(H)). Inone species, the constant region is essentially identical in allantibodies of the same isotype, but differs in antibodies of differentisotypes. Heavy chains γ, α and δ have a constant region composed ofthree tandem Ig domains, and a hinge region for added flexibility; heavychains μ and ε have a constant region composed of four immunoglobulindomains. The variable region of the heavy chain differs in antibodiesproduced by different B cells, but is the same for all antibodiesproduced by a single B cell or B cell clone. The variable region of eachheavy chain is approximately 110 amino acids long and is composed of asingle Ig domain.

In mammals, there are two types of immunoglobulin light chain denoted byλ and κ. A light chain has two successive domains: one constant domain(CL) and one variable domain (VL). The approximate length of a lightchain is 211 to 217 amino acids. Each antibody contains two light chainsthat are always identical; only one type of light chain, κ or λ, ispresent per antibody in mammals.

Although the general structure of all antibodies is very similar, theunique property of a given antibody is determined by the variable (V)regions, as detailed above. More specifically, variable loops, threeeach the light (VL) and three on the heavy (VH) chain, are responsiblefor binding to the antigen, i.e. for its antigen specificity. Theseloops are referred to as the Complementarity Determining Regions (CDRs).Because CDRs from both VH and VL domains contribute to theantigen-binding site, it is the combination of the heavy and the lightchains, and not either alone, that determines the final antigenspecificity.

An “antibody fragment” contains at least one antigen binding fragment asdefined above, and exhibits essentially the same function andspecificity as the complete antibody of which the fragment is derivedfrom. Limited proteolytic digestion with papain cleaves the Ig prototypeinto three fragments. Two identical amino terminal fragments, eachcontaining one entire L chain and about half an H chain, are the antigenbinding fragments (Fab). The third fragment, similar in size butcontaining the carboxyl terminal half of both heavy chains with theirinterchain disulfide bond, is the crystalizable fragment (Fc). The Fccontains carbohydrates, complement-binding, and FcR-binding sites.Limited pepsin digestion yields a single F(ab′)2 fragment containingboth Fab pieces and the hinge region, including the H-H interchaindisulfide bond. F(ab′)2 is divalent for antigen binding. The disulfidebond of F(ab′)2 may be cleaved in order to obtain Fab′. Moreover, thevariable regions of the heavy and light chains can be fused together toform a single chain variable fragment (scFv).

Pharmaceutically acceptable salts are for example acid addition saltsand basic salts. Acid addition salts are e.g. HCI or HBr salts. Basicsalts are e.g. salts having a cation selected from alkali or alkaline,e.g. Na+, or K+, or Ca2+, or an ammonium ion N+(R1)(R2)(R3)(R4), whereinR1 to R4 independently of each other mean: hydrogen, an optionallysubstituted C1-C6-alkyl group, an optionally substituted C2-C6-alkenylgroup, an optionally substituted C6-C10-aryl group, or an optionallysubstituted C6-C10-heteroaryl group. Further examples ofpharmaceutically acceptable salts are described in “Remington'sPharmaceutical Sciences” 17. ed. Alfonso R. Gennaro (Ed.), MarkPublishing Company, Easton, Pa., U.S.A., 1985 and in Encyclopedia ofPharmaceutical Technology.

Pharmaceutically acceptable solvates are for example hydrates.

It will be further apparent to those skilled in the art that variousmodifications and variations can be made to the present inventionwithout departing from the spirit and scope of the invention as it isdefined by the claims. Further, it is to be noted, that any referencenumerals used in the appended claims are not to be construed as limitingthe scope of the invention.

BRIEF DESCRIPTION OF THE FIGURES

In the following various embodiments of a data collection device inconnection with an injection device are described by making reference tothe drawings, in which:

FIG. 1 shows an longitudinal cross-section through an example of a handheld injection device,

FIG. 2 is a perspective view of the proximal end of the injection deviceof FIG. 1 ,

FIG. 3 is a side view of the dose tracking member, the limiter and thetrigger in an initial configuration,

FIG. 4 is another side view of the arrangement according to FIG. 3 aftera dose of a predetermined size has been set,

FIG. 5 shows a further configuration of the arrangement of FIGS. 3 and 4with the trigger and the limiter being depressed in distal direction,

FIG. 6 shows another example of a dose tracking member in an arrangementaccording to FIGS. 2 to 5 ,

FIG. 7 shows a perspective view of the arrangement of FIG. 6 ,

FIG. 8 is a cross-section A- A according to FIG. 5 with the dosetracking member in an allowable positional state,

FIG. 9 is a cross-section according to FIG. 8 with the dose trackingmember rotated by about 75° compared to the configuration of FIG. 8 ,

FIG. 10 shows a further cross-section according to FIG. 8 with the dosetracking member rotated by about 180° compared to the configuration ofFIG. 8 ,

FIG. 11 shows a longitudinal cross-section through another example of adose tracking member and a limiter in a proximal position,

FIG. 12 shows the arrangement according to FIG. 11 with the limiterdisplaced towards the distal direction compared to FIG. 11 ,

FIG. 13 shows another example of a proximal portion of an injectiondevice in a perspective view,

FIG. 14 shows the dose tracking member, a number sleeve and the limiteraccording to FIG. 13 in a perspective and isolated view,

FIG. 15 shows an isolated view of another example of a limiter,

FIG. 16 shows a cross-section of an another example of an injectiondevice with a limiter according to FIG. 15 and with the trigger in anidle position,

FIG. 17 shows a cross-section of the device according to FIG. 16 withthe trigger depressed in distal direction,

FIG. 18 shows a detailed and enlarged view of the distal end of thelimiter and the trigger in the configuration of FIG. 16 ,

FIG. 19 shows the configuration according to FIG. 18 with the triggerslightly displaced in distal direction and

FIG. 20 shows the distal end of the trigger and the limiter in theconfiguration according to FIG. 17 ,

FIG. 21 is a partially cut and perspective view of the dose trackingmember according to FIGS. 16 to 20 ,

FIG. 22 is an enlarged view of the limiter in engagement with the dosetracking member according to FIG. 21 ,

FIG. 23 shows a cross-section of another example of an injection devicewith the dose tracking member in an allowable positional state,

FIG. 24 shows a cross-section of the example of FIG. 23 with the limiterdisplaced towards the proximal end,

FIG. 25 is an isolated perspective view of the limiter,

FIG. 26 is a perspective and partially cut view of the device accordingto FIGS. 23 to 25 ,

FIG. 27 is a schematic illustration of the interaction between thekeying features of the limiter and the dose tracking member,

FIG. 28 shows the component of FIG. 27 with the keying feature of thelimiter displaced in proximal direction,

FIG. 29 is illustrative of a further configuration of the keyingfeatures of FIGS. 27 and 28 ,

FIG. 30 shows a further configuration of the keying features of thelimiter and the dose tracking member,

FIG. 31 is illustrative of a further configuration of the keyingfeatures of the limiter and the dose tracking member,

FIG. 32 shows the proximal end of the injection device with the keyingfeatures of FIGS. 23 to 31 with the trigger in an idle position and

FIG. 33 shows the device according to FIG. 32 with the trigger in thedose dispensing position.

DETAILED DESCRIPTION

The injection device 1 as shown in FIGS. 1 and 2 comprises a housing 10of elongated shape. The injection device 1 is configured as a handheldinjection device. The housing 10 is of substantially tubular shape. Itextends from a proximal end 4 to a distal end 5. The housing 10comprises a cartridge holder 13 forming a distal end of the housing 10and further comprises a main housing component 14 forming a proximal endof the housing 10. The cartridge holder 13 is configured to accommodatea cartridge 20. The cartridge 20 comprises a barrel 21 filled with aliquid medicament 6. Near its proximal end the barrel 21 is sealed witha bung 22 that is displaceably arranged inside the barrel 21 forexpelling of the liquid medicament 6 through the distal end of thecartridge 20. Typically, the distal end of the cartridge 20 is sealed bya pierceable seal 23. The distal end of the cartridge 20 is typicallylocated near and inside the distal end of the cartridge holder 13. Thedistal end of the cartridge holder 13 comprises an outer threadedsection to releasably engage with a correspondingly shaped threadedsection of a needle hub (not illustrated).

The fastening of the needle hub to the distal end of the cartridgeholder 13 comes along with a penetration of the pierceable seal 23. Inthis way the double -tipped injection needle gains access to theinterior of the cartridge 20. The injection needle is hence in fluidcommunication with the medicament 6 inside the cartridge. By exerting adistally directed pressure onto the bung 22 the medicament 6 can beexpelled through the injection needle from the interior of the cartridge20 and into biological tissue.

A distally directed advancing motion of the bung 22 is provided by apiston rod 30 of a windup expelling mechanism 2 that is located insidethe housing 10, in particular inside the main housing component 14. Theinjection device 1 further comprises a dose setting mechanism 3. Thedose setting mechanism 3 is also located and accommodated inside thehousing 10, in particular inside the main housing component 14. Thewindup expelling mechanism 2 and the dose setting mechanism 3 comprisesnumerous mechanically interacting components. There may be provided somecomponents of the injection device 1 that belong to both, the dosesetting mechanism 3 and to the windup expelling mechanism 2.

The specific implementation of an exemplary injection device will bedescribed later on. Typically, the dose setting mechanism provides anindividual dialing or setting of a dose of variable size. For this theuser may grab a handle 90 provided near the proximal end 4 of theinjection device 1. Setting of a dose may be conducted by rotating thehandle 90 in a clockwise or counterclockwise direction, i.e. in a doseincrementing direction. For dispensing of the dose of the medicament theuser has to depress the trigger 50 at the proximal end 4 of theinjection device thereby initiating a dose expelling or dose dispensingprocedure.

The windup expelling mechanism 2 has a mechanical energy reservoir 75.The mechanical energy reservoir 75 may comprise a helically shaped drivespring. During dose setting the mechanical energy reservoir 75 may bearmed or biased. A driving motion or a driving momentum applied to thehandle 90 may serve to increase the energy level stored in themechanical energy reservoir 75. During dose dispensing and whendepressing the trigger 50 at least a portion of the previously storedmechanical energy is released. Consequently, the mechanical energyprovided by the mechanical energy reservoir 75 is transferred into adistally directed driving motion of the piston rod 34 thereby urging thebung 22 towards the distal end 5.

The injection device 1 and the dose setting mechanism 3 are configuredto provide setting and dispensing of doses of the medicament 6 ofvariable size. The user himself may determine the amount of medicamentto be injected in a dose expelling procedure. A user may for instanceselect a dose between 0 units and 120 units of a medicament, e.g. arespective amount of international units (IU) of insulin. The injectiondevice 1 as described herein provides a limitation of generallyavailable dose sizes to a number of predetermined dose sizes. The dosesetting mechanism and the windup expelling mechanism are configured toblock or to prevent dispensing of a dose of a medicament having aninappropriate size. In this way the injection device can is limited andconfigured to enable a dose dispensing action only when the previouslyset dose is within a range of allowable doses to be set and dispensed.

For all other dose sizes the dose setting mechanism and/or the windupexpelling mechanism is blocked. In this way and when a user sets ordials a dose of the medicament of an inappropriate size, e.g. a dosebeing too large or a dose being too small for a specific therapeutictreatment the dose actually set cannot be dispensed.

In order to achieve this blocking functionality depression of thetrigger 50 at or near the proximal end 4 of the injection device 1 iseffectively blocked.

One embodiment of such a blocking function is now described in FIGS. 3to 10 . In this example the injection device 1 comprises a dose trackingmember 40, a limiter 60 and a trigger 50. The dose tracking member 40 ismovably arranged inside the housing 10, in particular inside theproximal or main housing component 14. The dose tracking member 40 isrotatable relative to the housing 10 within a range of positionalstates. As it is apparent from a comparison of FIGS. 3, 4 and 5 , thedose tracking member 40 can be displaced in a longitudinal direction ofthe injection device 1. In FIG. 3 , the dose tracking member 40 is in aninitial configuration that may correspond to a zero-dose configurationand hence to a configuration of the dose setting mechanism 3 where thedose actually set equals 0.

By setting of a dose and e.g. when rotating the handle 90 in a doseincrementing direction, e.g. clockwise as seen in FIG. 2 , the dosetracking member 40 will be subject to a distally directed motion. Atleast during dose setting the dose tracking member 40 is rotationallycoupled or rotationally locked to the handle 90. A rotation of thehandle 90 in a clockwise direction directly leads to a correspondingrotation of the dose tracking member 40. In the present example the dosetracking member 40 is engaged with the housing 10 by a slotted link 12.For instance, the slotted link 12 comprises two mutually correspondingthreaded structures on the inside facing sidewall portion of theproximal housing component 14 and on the outer circumference of the dosetracking member 40.

The slotted link 12 may be formed by a threaded section 11 on the insidefacing sidewall of the main housing component 14 and by a keyingstructure 41 on the outer circumference of the dose tracking member 40.The keying structure 41 may comprise a helical thread protrudingradially outwardly from a cylindrically shaped outer surface of the dosetracking member 40.

The dose tracking member 40 may comprise a sleeve -shaped geometry. Itmay be substantially cylindrically -shaped.

Due to the slotted link 12 between the dose tracking member 40 and thehousing 10 the dose tracking member 40 is subject to a combinedrotational and axial motion as the handle 90 is turned relative to thehousing 10. As the dose tracking member 40 is turned or as the dosetracking member 40 is rotated relative to the housing 10 it assumesdifferent positional states. Hence, the axial position as well as adegree of rotation gradually changes as the dose tracking member 40 isrotated relative to the housing 10. Any positional states, i.e. anyaxial position as well as any rotational position of the dose trackingmember relative to the housing 10 is characteristic and unique for adose of a specific size.

The limiter 60 is rotationally fixed to the housing 10. It is axially,e.g. axially slidable displaceable relative to the housing 10 within alimited range. The limiter 60 is operationally engageable with the dosetracking member 40 for blocking actuation of the trigger 50 when thedose tracking member 40 is in one of a number of predetermined sectionsof the range of positional states. In other words, if a non-allowed dosesize has been set and if the dose tracking member 40 is hence located ina respective positional state the dose tracking member is operablyengaged with the limiter 60 so as to prevent a distally directeddisplacement of the limiter 50. In this way and since the limiter 60 isalso axially engageable with the trigger 50, the trigger 50 cannot bedisplaced towards the distal end 5. The trigger 50 is axially locked orblocked and is hence hindered to be displaced in a dose dispensingposition d as indicated in FIG. 5 .

The operational engagement between the dose tracking member 40 and thelimiter 60 comprises a first pair of keying features and a second pairof keying features that are located on the limiter 60 and on the dosetracking member 40, respectively. In FIG. 4 the limiter 60 comprises twokeying features, namely a first keying feature 63 and a second keyingfeature 64. The first and second keying features 63 and 64 are locatedand are separated at a circumferential offset relative to each other.The first keying feature 63 and the second keying feature 64 bothcomprise a radially inwardly extending protrusion to engage with acorrespondingly shaped keying structure 41 on the outside of the dosetracking member 40. As it is apparent from FIG. 4 , the first and secondkeying features 63, 64 of the limiter 60 are in axial abutment with theradially outwardly protruding keying structure 41 of the dose trackingmember 40. In this way and as long as distally facing edge of face ofthe keying features 63, 64 is in axial abutment with a proximal sideedge of the keying structure 41 the limiter 60 is hindered to bedisplaced in longitudinal direction, in particular towards the distalend 4 of the injection device 1.

As indicated in FIG. 4 , the keying structure 41 of the dose trackingmember 40 comprises a first keying feature 43 and a second keyingfeature 44. Here, the keying features 43, 44 comprise a recess or aninterruption in the keying structure 41. In circumferential directionthe keying features 43, 44 are at least as large as the extension of thefirst and the second keying features 63, 64 of the limiter 60. In aparticular positional state of the dose tracking member 40 thatcorrespond to an allowable size of a dose to be dispensed the keyingfeatures 43, 44 of the dose tracking member 40 are aligned axially oraxially inline with the correspondingly shaped keying features 63, 64 ofthe limiter 60.

Then, as shown in FIG. 5 , the limiter 60 can be displaced in distaldirection when depressing the trigger 50 accordingly. When subject to adistally directed displacement the keying feature 63 of the limiter 60is axially displaced through the keying feature 43 on the dose trackingmember 40, and hence through the recess or gap formed by the keyingfeature 43. Likewise and simultaneously also the keying feature 64 willslide through the correspondingly shaped keying feature 44 of the dosetracking member 40.

Once the keying features 63, 64 of the limiter 60 have traveled past andthrough the correspondingly shaped keying features 43, 44 of the dosetracking member 40 the dispensing procedure can be triggered. During thedose dispensing procedure the dose tracking member 40 will be subject toa reverse motion until it returns and arrives in the initial zero-doseposition as shown in FIG. 3 . When reaching the zero dose configurationthe keying features 63, 64 of the limiter 60 will be aligned withcorrespondingly shaped zero-dose keying features of the dose trackingmember 40 that allow a proximally directed movement of the limiter 60relative to the dose tracking member 40. Then and at the end of a dosedispensing procedure the user may release the trigger 50, which underthe effect of a trigger spring 51 will return into its idle position ias shown in FIGS. 3 and 6 .

The trigger 50 comprises a circular or cylindrically -shaped buttonportion 53 with a closed proximal end face 54. The button portion 53comprises a cylindrically -shaped sidewall from which numerous strutportion 52 extend axially and towards the distal end 5. The strutportions 52 each comprise a first radial protrusion 55 and a secondradial protrusion 56 as shown in FIGS. 2 and 3 . The radial protrusion55, 56 may each comprise a radially outwardly extending rib. The firstradial protrusion 55 is located at a distal end of the strut portion 52and protrudes radially outwardly. The first radial protrusion 55 isengaged and connected to a correspondingly shaped radially inwardlyextending rim or protrusion 68 of the limiter 60. A proximal end face ofthe first protrusion 55 is in axial abutment with a distally facing endface of the protrusion 68 on the inside sidewall of the proximal endsection 69 of the limiter 60. In this way and when urged in proximaldirection by the trigger spring 51 the trigger 50 drags the limiter 60back into its initial position as shown in FIG. 3 .

The second radial protrusion 56 protruding radially outwardly from theaxially extending strut portion 52 is located proximally from theproximal end of the limiter 60. The second radial protrusion 56 maycomprise a radial extension that is larger than an inner diameter of theproximal end section 69 of the limiter 60. In this way and whendepressing the trigger 50 in distal direction the second radialprotrusion 56 axially abuts with a proximal end face 67 of the limiter60. The proximal end face 67 may be provided on an annular shapedproximal end section 69 of the limiter 60. The first and second keyingfeatures 63, 64 are located distally from the proximal end section 69.They are provided on first and second engaging sections 61, 63 extendingaxially and distally from the proximal end section 69. Typically and asshown in FIGS. 2 to 10 the keying features 63, 64 are provided at aninside facing portion of a first leg 65 forming the first engagingsection 61 and a second leg 66 forming the second engaging section 62.The engaging section 61, 62 and hence the legs 65, 66 have a limitedcircumferential dimension or extension as shown in FIG. 7 . The engagingsection 61, 62 or the legs 65, 66 may comprise a circumferentialextension of the less than 45°, less than 30°, less than 20° or lessthan 15°. A limited circumferential dimension of the engaging sections61, 62 or of the respective legs 65, 66 is beneficial to reduce apackage size of the device. The dose tracking member 40 can bethreadedly engaged with the housing 10 by means of at least one of thekeying structures 41, 42. A threaded portion of the housing 10threadedly engaged with at least one of the keying structures 41, 42 ofthe dose tracking member 40 may be located and arranged axiallyoverlapping with the engaging sections 61, 62 or may be arranged axiallyoverlapping with legs 65, 66 of the limiter 60.

Alternatively, the limiter 60 may also comprise a cylindrical structurewith a closed circumferential side wall, wherein the first and thesecond engaging sections 61, 62 are integrated into the sidewall of thelimiter 60. Here, the engaging sections 61, 62 may each comprise aprotrusion extending radially inwardly from an inside surface of thecylindrical sidewall of the limiter 60. With a cylindrically -shapedlimiter 68 threaded engagement of the dose tracking member 40 with thehousing 10 may be located axially offset from the limiter 60.

The first engaging section 61 comprises the first keying feature 63 andthe second engaging section 62 comprises the second keying features 64.As it is shown in FIGS. 4 to 6 the first and second keying features 63,64 of the limiter 60 are arranged diametrically opposite around theouter circumference of the dose tracking member 40. The offset of thefirst and the second keying features 63, 64 may be in a range of 180°.In this way and when in a blocking configuration and hence in a blockingposition b as indicated in FIG. 4 the first and the second keyingfeature 63, 64 of the limiter 60 are in simultaneous axial abutment withat least one of the keying structures 41 of the dose tracking member 40.

Typically, the first and the second keying features 63, 64 are in axialabutment with the first and with the second keying structures 41, 42 andin particular with first and second keying features 43, 44 of the dosetracking member 40.

In this way and when exerting a distally directed force to the trigger50 the limiter 60 will experience a corresponding force effect in adistal direction through the engagement of the strut portion 52 with theproximal end section 69 of the limiter 60. Since the first and thesecond keying features 63, 64 are both in axial abutment with the keyingstructure 41 on the outside circumference of the dose tracking member40, the axial force effect acting on the trigger 50 and hence on thelimiter 60 distributes among the first and the second keying features63, 64 and among the first and second engaging sections 61, 62.

The axial load on the dose tracking member 40 is balanced in this way.Having a first and a second keying feature 63, 64 that are spaced apartfrom each other in the circumferential direction prevents andcounteracts any tilting motion or cant of the limiter 60 relative to thedose tracking member 40. In addition, axial load transferred from thelimiter 60 to the dose tracking member 40 is introduced rathersymmetrically and homogeneously into the dose tracking member 40. Inthis way also a tilting motion or cant of the dose tracking member 40inside the housing 10 can be reduced or can be entirely eliminated.

Typically, there are provided two pairs of keying features on the dosetracking member 40 and on the limiter 60. The dose tracking member 40and the limiter 60 are both configured such that a first pair of keyingfeatures and a second pair of keying features simultaneously engage orsimultaneously disengage. When the first keying feature 63 of thelimiter 60 axially aligns with a first keying feature 43 on the dosetracking member 40 also the second keying feature 64 of the limiter 60axially aligns with the second keying feature 44 of the dose trackingmember 40. It is then that each pair of keying features, namely a firstpair of the keying features 43, 63 and a second pair of keying features44, 64 both allow or prevent axial displacement of the limiter 60relative to the dose tracking member 40 in distal direction.

For setting of a dose the dose tracking member 40 may be subject to arotation larger than 120° or larger than 180°. Moreover, the dosetracking member 40 may be subject to more than one or more than twoentire revolutions with the longitudinal axis as an axis of rotation. Inorder to have a unique and distinct encoding on the dose tracking member40 it is conceivable that the geometry of the keying features 63, 64 ofthe limiter 60 are different so that only a first keying features 63 ofthe limiter 60 is configured to align and to pass through a first keyingfeature 43 of the dose tracking member 40 and that a second keyingfeature 64 of the limiter 60 does not match with the first keyingfeature 43 of the dose tracking member 40. The second keying features 64of the limiter 60 may only match and may only properly align with thesecond keying feature 44 of the dose tracking member 40. If the firstand the second keying features of the dose tracking member 40 and of thelimiter 60 should be equidistantly spaced apart in circumferentialdirection, e.g. if two keying features should be separated by about 180°or if three keying features should be separated by about 120° there willbe only one distinct and unique positional state of the dose trackingmember 40 at which the keying features of the dose tracking member 40and the limiter 60 properly align.

Such a situation is shown in FIGS. 8 through 10 . There, the keyingfeatures 63, 64 of the limiter 60 are mirror symmetric but notrotationally symmetric. Hence, the keying feature 63 and the keyingfeatures 64 are of substantially identical shape. The keying feature 63as shown on top of FIG. 8 may be transferred into the keying feature 64near the bottom of FIG. 8 by way of a reflective projection with regardsto a horizontal line extending through the center of the limiter 60. Asit is apparent from FIG. 9 the dose tracking member 40 comprises a firstand a second keying feature 43, 44 each of which having a geometricshape that matches with only one of the geometric shapes of the keyingfeatures 63, 64 of the limiter 60. Only in one positional state of thedose tracking member 40 as shown in FIG. 8 the first keying feature 63of the limiter 60 matches and axially aligns with the first keyingfeature 43 of the dose tracking member 40. Simultaneously, also thesecond keying feature 64 axially aligns with the second keying feature44 of the dose tracking member 40. As the dose tracking member 40 isrotated by e.g. 180°, as shown in FIG. 10 , the keying feature 64 of thelimiter 60 remains in axial engagement with a section 43 a of the keyingfeature 43 of the dose tracking member 40.

In the example as shown in FIGS. 8 through 10 the mutually correspondingkeying features 43, 44, 63, 64 comprise an L-shaped geometry andtherefore provides a symmetry breaking feature. Only in one of theillustrated positional states, which is shown in FIG. 8 the position andshape of the keying features 43, 43, 63 and 64 mutually match therebyallowing that the keying features 63, 64 of the limiter 60 axially slideor pass through the keying features 43, 44 of the dose tracking member40.

In the present example the first and second keying features 63, 64 ofthe limiter 60 are provided and configured as a radially inwardlyextending protrusion located near a distal end of the first and secondlegs 65, 66, respectively.

The first and second keying features 43, 44 of the dose tracking member40 are provided as recesses or as axial through openings through thehelically shaped keying structures 41, 42 on the outside circumferenceof the dose tracking member 40. There may be provided two separatekeying structures 41, 42 on the outside circumference of the dosetracking member 40. As shown in FIG. 6 , there is provided a firstkeying structure 41 in form of a first helical thread and a secondkeying structure 42 in form of a second helical thread.

The first and the second keying structures 41, 42 are arranged at apredefined axial offset ‘O’ as indicated in FIG. 6 . Both, the first andthe second keying structures can be encoded individually andindependently. In typical examples the first and the second keyingstructures are encoded pairwise so as to provide simultaneous engagementor release with correspondingly shaped keying features of the limiter60. The keying structures comprise keying features 43, 44 that match andalign with correspondingly shaped keying features 63, 64 of the limiter60 simultaneously. Typically, the offset ‘O’ is larger than or equal tothe magnitude of the axial sliding motion of the limiter 60 from ablocking position b as shown in FIG. 3 and a dose dispensing position dor release position r as shown in FIG. 5 . As it is further indicated inFIG. 6 , the axial offset between the first and the second keyingstructure 41, 42 is smaller than the axial separation of 2 neighboringrevolutions of the helically shaped keying structures 41, 42.

As seen for instance in axial direction, the second keying structure 42,hence the second helical thread is located at the predefined proximaloffset ‘O’ from the first keying structure 41, i.e. from the firsthelical thread. Then and proximally adjacent to the second keyingstructure 42 there is provided a display portion 45 having a largeraxial extension than the distance between or the axial offset betweenthe convoluted keying structures 41, 42. The display portion 45 hasprinted numbers thereon to show up in a dose indicating window of thehousing 10.

The keying features 63, 64 of the limiter 60 may be positioned at thesame or identical axial position or they may be axially offset as shownin FIG. 5 . Since the first and second keying features 63, 64 are inthreaded or positive engagement with different circumferential portionsof the first and the second keying structures 41, 42 this axial offsetbetween the first and the second keying features 63, 64 is due to thepitch of the helically shaped keying structures 41, 42. As it is shownin FIGS. 6 and 7 the first keying structure 41 is located and positioneddistally from the second keying structure 42. The radially inwardlyextending keying feature 63 of the limiter 60 is axially positionedbetween the first and second keying structures 41, 42.

As the first keying features 63 of the limiter 60 aligns with the keyingfeature 43 of the first keying structure 41 also the second keyingfeature 64 of the limiter 60 aligns axially with a correspondinglyshaped keying feature 44 of the second keying structure 42 (not shown).Since the keying features 43, 44 of the dose tracking member 40 arelocated at a predefined circumferential offset the second keying feature64 of the limiter 60 move through the second keying feature 44 of thedose tracking member and will enter the intermediate space between thefirst and the second keying structure 42. A distal edge of the secondkeying feature 44 may then abut and engage with a proximal edge of thefirst keying structure 41. This engagement may limit the distallydirected displacement of the limiter 60.

In order to allow and to support a dose dispensing action the axialoffset ‘O’ between the first and the second keying structures 41, 42 islarger than or at least equal to an axial displacement of the limiter 60and/or of the trigger 50 to disengage a clutch for switching theinjection device 1 from the dose setting mode into the dose dispensingmode.

The mutually corresponding keying features 63, 64 and 43 and 44 of thelimiter and the dose tracking member are arranged and configured suchthat during depressing of the trigger 50 and while the limiter 60 isdisplaced in distal direction a clutch of the windup expelling mechanism2 disengages and releases before the second keying feature 64 of thelimiter gets in axial abutment or axial engagement with the first keyingstructure 41 of the dose tracking member.

With almost all examples as described herein there are provided at leasttwo pairs of keying features of the dose tracking member 40 and thelimiter 60 that simultaneously engage and simultaneously disengage. Inthis way a redundant locking or blocking configuration betweennon-aligned and/or non-matching keying features of the dose trackingmember 40 and the limiter 60 can be provided. In a lockingconfiguration, in which the at least first and second keying features63, 64 of the limiter 60 axially engage the first keying structure 41and/or the second keying structure 42 of the dose tracking member 40axial load acting on the trigger 50 and been transferred to the limiter60 may homogeneously or equally distribute among the pairs ofinterengaging or interengaged keying features 43, 63 and 44, 64.

In the example as shown in FIGS. 3 to 10 the first and the second keyingstructures 41, 42 of the dose tracking member 40, hence a first and asecond helical thread are arranged intertwined or in a convoluted waywith a well-defined axial offset with respect to each other.

In another example as shown in FIGS. 11 and 12 the first and the secondkeying structures 241, 242 are also provided on an outside circumferenceof a dose tracking member 240. The dose tracking member 240 alsocomprises a cylindrical or tubular shape. It may be engaged with thehousing 10 by a slotted link 12 as described in connection with theexample as shown in FIG. 2 .

The first and the second keying structures 241, 242 each comprise ahelically shaped continues protrusion extending along the outercircumference of the dose tracking member 240. As it is apparent fromFIGS. 11 and 12 the first keying structure 241 comprises a radialextension r1 that is smaller than a radial extension r2 of the secondkeying structure 242.

Both keying structures 241, 242 comprise at least one keying feature243, 244. As shown in FIG. 11 the second keying structure 242, i.e. theone with the larger radial extension comprises a second keying feature244 in form of an axial recess or axial slit exclusively in the outermost radial portion of the keying structure 242. Radially underneath thefirst keying structure 241 is void of such a recess or slit. The firstkeying structure 241 comprises a keying feature 243 in form of a recessor slit located elsewhere. As shown here, the keying feature 243intersects both, the first keying structure 241 and the second keyingstructure 242 in axial direction. The keying feature 244 only axiallyintersected the outer most second keying structure 242 but has nooverlap with the first keying structure 241.

The limiter 60 of which only the distal section is shown in FIGS. 11 and12 comprises first and second engaging section 61, 62 with first andsecond keying features 63, 64. Also here, the first engaging section isprovided on a first leg 65 and the second engaging section 62 isprovided on a second leg 66. The first keying feature 63 comprises aradially inwardly extending protrusion at the first engaging section 61,hence at an inside facing surface of the first leg 65. Correspondingly,the second keying feature 64 comprises a radially inwardly extendingprotrusion provided at an inside facing portion of the second engagingsection 62 and hence at the second leg 66. As it is apparent from FIGS.11 and 12 the keying features 63, 64 have different radially inwardlyprotruding dimensions. The radial extension of the first keying feature63 is larger than the radial extension of the second keying features 64.

Only in the configuration as shown in Fig. lithe first keying features63 of the limiter 60 is aligned with the first keying feature 243intersecting and extending through both, the first keying structure 41and the second keying structure 42. In the same configuration it is thesecond keying feature 64 of the limiter 60 that aligns with the secondkeying feature 244 of the second keying structure 242. In thisconfiguration the limiter 60 with its keying features 63, 64 is allowedto pass the keying structures 241, 242 in axial direction, hence towardsthe distal end 5 of the injection device 1.

In another configuration, wherein the dose tracking member 240 would berotated by 180° compared to the configuration as shown in FIGS. 11 and12 the first keying feature 63, hence the first protrusion of thelimiter 60 would be aligned with the second keying feature 244 of thedose tracking member. Since the radial depth of the recess of the secondkeying feature 244 is smaller than the radially inwardly protrudingextension of the first keying feature 63 the first keying feature 63would be hindered to pass through the keying feature 244. As aconsequence, the radially inwardly protruding keying features 63 wouldget in axial abutment with a proximal abutment face of the first keyingstructure 241. The distally directed displacement of the limiter 60would be blocked.

The FIGS. 11 and 12 are illustrative of an example, wherein the secondkeying structure 242 is radially offset from the first keying structure241. Here, the first and the second keying structures 241, 242 mayaxially overlap or may axially coincide. In effect, the total axialelongation on the axial space occupied on the outer circumference of thedose tracking member 240 can be reduced compared to the example as shownin FIG. 6 . The axial extension or axial width of a circumferentialportion of the first and the second keying structures 241, 242 can besmaller than the axial dimensions of a circumferential portion of thefirst and the second keying structures 41, 42 of the dose trackingmember 40 of FIG. 6 .

Consequently, the axial extension of a display portion 245 axiallyadjacent to the first and the second keying structures 241, 242 can beincreased. Numbers printed in or on the display portion 245 can beenlarged while keeping the pitch of the helically shaped keyingstructures 241, 242 in the same range or at the same level compared tothe keying structures 41, 42 of the example as shown in FIGS. 3 to 10 .

In the examples as shown in FIGS. 1 to 12 and 15 to 33 the dose trackingmember 40, 240 provides a double function. Axially between neighboringconvolutions of the helically shaped keying structures 41, 42, 241, 242,there is provided a display portion 45, 245 that has sequence of numberson an outside facing surface. Therefore, the dose tracking member 40,240 also serves as a number sleeve 70 with a helical sequence ofconsecutive numbers printed there on. The numbers show up in a dosagewindow of the main housing component 14 as the number sleeve 70 or dosetracking member 40, 240 is rotated in dose incrementing or dosedecrementing direction.

In the example as shown in FIGS. 13 and 14 there is provided a separatenumber sleeve 170 in addition to a dose tracking member 140. The numbersleeve 170 is threadedly engaged with the housing 10. There is provideda slotted link 12 between the housing 10 and the number sleeve 170. Theslotted link 12 comprises a radially inwardly extending threaded section11 that is threadedly engaged with a correspondingly shaped helicallywound threaded section 171 on the outer circumference of the numbersleeve 70. The threaded section 171 is a recessed threaded section andextends radially inwardly from the outside surface of the number sleeve170.

As shown in FIG. 14 , the number sleeve 170 comprises a display portion172 between axially neighboring convolutions of the threaded section171. Here and in comparison to the examples as shown in FIGS. 1 to 12the axial dimension of the display portion 172 is comparatively largesince the number sleeve 170 comprises only a single threaded section171. Also here, the display portion 172 is provided with a helicalsequence of consecutive numbers that show up in the dosage window of thehousing 10 of the injection device 1.

The dose tracking member 140 also comprises a sleeve like shape. It isaxially confined in a proximal portion of the main housing component 14.The dose tracking member 140 comprises a circumferential engagingsection 146 that is axially engaged with a correspondingly shapedengaging section 16 at the inside of the sidewall of the housing 10.Here, the engaging section 146 provided at a distal end of the dosetracking member 140. The engaging section 146 is configured to rotatewhile in engagement with the engaging section 16 of the housing 10. Theengaging section 16 comprises a radially inwardly extending protrusionor a correspondingly shaped rib engaging with a the groove shapedengaging section 146 of the dose tracking member 140. In this way thedose tracking member 140 is free to rotate relative to the housing 10.By means of the mutual engagement of the engaging sections 146 and 16the dose tracking member 140 is axially fixed to the housing 10.

The dose tracking member 140 is permanently rotationally locked to thenumber sleeve 170. This interlock is provided by a keyed engagement ofthe number sleeve 170 and the dose tracking member 140. The numbersleeve 170 comprises an axially extending keying structure 173 extendingin axial direction on the outer circumference of the number sleeve 170.In the example as shown in FIG. 14 the keying structure 173 comprises anaxially extending recessed slot. The dose tracking member 140 enclosingthe outer circumference of the number sleeve 170 comprises acorrespondingly shaped radially inwardly extending pin or a respectiveprotrusion that rests inside the keying structure 173.

In this way, the number sleeve 170 is free to slide axially relative tothe dose tracking member 140. Due to the keyed engagement between thenumber sleeve 170 and the dose tracking member 140 the dose trackingmember 140 is permanently rotationally locked to the number sleeve 170.

A rotation of the number sleeve 170 during a dose setting procedure orduring dose expelling is therefore equally transferred to a respectiverotation of the dose tracking member 140. As indicated on FIG. 14 thedose tracking member comprises a first keying structure 141 and a secondkeying structure 142. Here, the first and the second keying structures141, 142 are equidistantly arranged in axial direction. Hence, the axialoffset between the first keying structure 141 and the second keyingstructure 142 substantially equals the axial offset between the secondkeying structure 142 to the first keying structure 141. Furthermore, thedose tracking member 140 is void of a display portion. The overall axialextension of the dose tracking member 140 can be reduced andminiaturized compared to the example as described in connection withFIGS. 1 to 12 or in connection with any one of the FIGS. 15 to 33 .

Apart from that the function of the first and second keying structures141, 142 is substantially identical to the function of the keyingstructures 41, 42 described above in connection with FIGS. 1 to 12 . Thefirst keying structure 141 comprises a first outer thread and the secondkeying structure 142 comprises a second outer thread. The first and thesecond keying structures 141, 142 comprise an identical pitch. The firstkeying structure 141 comprises a first keying feature 143. The secondkeying structure 142 comprises a second keying feature 144. The firstand second keying features 143, 144 are configured as an axial recess,as an axial slot or as an axial interruption of the respective keyingstructures 141, 142.

The limiter 160 also comprises a first engaging section 161 and a secondengaging section 162. The first engaging section 161 is provided with afirst keying feature 163 extending radially inwardly from a distal freeend of the first engaging section 161. The first engaging section 161comprises a first leg 165 extending in distal direction from a proximalend section 169 of the limiter 160.

In a similar way also the second keying feature 164 is provided near oron a distal free end of the second engaging section 162. The secondengaging section 162 comprises a second leg 166. Also the second leg 166and the second engaging section 162 extend substantially in distaldirection from the proximal end section 169 of the limiter 160. Asillustrated in FIG. 14 , the proximal end section 169 comprises a flatan annular structure with a central through opening 168. The proximalend section 169 resembled a flat disk. A border 167 of the throughopening 168 has a stepped down recess to receive a radially outwardlyextending flange 26 on an outside surface of a drive sleeve 25.

The drive sleeve 25 extends axially through the number sleeve 170 andaxially through the dose tracking member 140. The flange 26 is in axialabutment with the border 167 of the through opening 168. As shown inFIG. 13 , the flange 26 is located proximally from the through opening168. A distally facing age of the flange 26 is in axial abutment with aproximally facing edge of the border 167. As further illustrated in FIG.13 an inside facing surface of the button portion 53 of the trigger 50is axially engageable with a proximal end face 27 of the drive sleeve25. In this way and by depressing the trigger 50 in distal direction thedrive sleeve 25 is displaceable in distal direction. By means of theaxial abutment of the flange 26 with the border 167 a distally directedadvancing motion of the drive sleeve 25 is transferred into acorresponding distally directed sliding displacement of the limiter 160.This distally directed displacement of the limiter 160 is only allowedand possible if the keying features 163, 164 thereof are aligned withcorrespondingly shaped and correspondingly positioned keying features143, 144 of the dose tracking member 140.

The limiter 160 as shown comprises at least two engaging sections,namely with a first engaging section 161 and a second engaging section162. It is possible to have three or more equidistantly arrangedengaging sections 161, 162 arranged around the outer circumference ofthe dose tracking member 140.

In FIGS. 15 to 22 another implementation of limiter 260 and the trigger250 is shown. Here, the trigger 250 combines the trigger 50 and thehandle 90 as described with regards to the example of FIG. 1 or 2 . Thecombined trigger/handle 250 comprises a sleeve like shape with a closedbottom 251 forming a proximal end face 252. The trigger 250 comprises asidewall 253. The sidewall 253 comprises a distal end section 254. Thetrigger 250 comprises a cup shaped receptacle, wherein the sidewall 253and the bottom 251 cover and enclose a proximal end 4 of the injectiondevice 1. The trigger 250 is rotatably mounted to the drive sleeve 25.The trigger 250 comprises an axially extending stem 255 extending in thedistal direction from the inside of the bottom 251. The stem 255comprises a radially outwardly extending flange section 256 by way ofwhich the trigger 250 is axially engaged with the drive sleeve 25. Thedrive sleeve 25 comprises radially inwardly extending protrusions 28 inaxial engagement with the outwardly extending flange section 256.

There is further provided an interface member 210 that is selectivelyrotationally engageable with the drive sleeve 25. At an inside surfaceof the sidewall 253 and adjacent to the button 251 there is provided asplined feature 258 of the trigger 250 permanently rotationally engagedwith the interface member 210. The interface member 210 comprises acorrespondingly shaped splined feature 211 on its outer circumference.The interface member 210 is of disk -like shape. The interface member210 further comprises an axial central through opening 212 to receivethe drive sleeve 25 and the stem 255 axially there through. On theinside of the through opening 212 there is arranged another splinedfeature 214 rotationally locked or rotationally lockable to acorrespondingly shaped splined feature 29 on the outer circumference ofthe drive sleeve 25.

In the idle position i of the trigger 250 as shown in FIG. 16 thesplined features 214, 29 are in engagement. Hence, the splined features29, 214 axially overlap. In this way, the interface member 210 isrotationally locked to the drive sleeve 25. Since the interface member210 is permanently rotationally locked to the trigger 250 via thesplines 211 and 258 the trigger 250 is rotationally locked to the drivesleeve 25 as long as the trigger 250 is in the proximal idle position i.By depressing the trigger 250 in distal direction so as to arrive in thedose dispensing position the inside facing portion of the button 251gets in axial abutment with the proximal end face 27 of the drive sleeve25. In this way the drive sleeve 25 is displaced towards the distaldirection. Consequently and since the interface member 210 is axiallylocked or axially connected to the limiter 260 the splined engagement ofthe interface member 210 and the drive sleeve 25 is released asindicated in FIG. 17 .

The distally directed displacement of the drive sleeve 25 is such thatthe splined features 29 arrive at a distal position in which theydisengage from the splined features 214. In this way and when reachingthe dose dispensing position d as indicated in FIG. 17 the drive sleeve25 is free to rotate under the action of the mechanical energy reservoir75 while the trigger 250 is held in a nonrotating dose dispensingposition, e.g. through the action of a thumb of a user.

Also with the example as shown in FIGS. 15 to 22 the limiter 260 isrotationally locked to the housing 10, in particular to the main housingcomponent 14. The limiter 260 comprises a first engaging section 261with a radially inwardly extending first keying feature 263. The firstkeying feature 263 and the first engaging section 261 are provided on afirst axially extending leg 265. The second keying feature 264 islocated on a radial inside of an axially extended second leg 266 forminga second engaging section 262. Also here, the first and the secondengaging sections 261, 262 as well as the respective keying features263, 264 are located at diametrically opposite to each other and withregard to the cylindrical geometry of the dose tracking member 40. Thedose tracking member 40 is shown in a partially cut view in FIG. 21 . Ina real example, the dose tracking member 40 comprises a tubular orcylindrical shape with a closed outer cylindrical sidewall.

The dose tracking member 40 also provides a number sleeve 70. The dosetracking member 40 comprises a first keying structure 41 with at least afirst keying feature 43. Typically, the dose tracking member 40 alsocomprises a second keying structure with at least a second keyingfeature 44. Here, the keying features 41, 42 are provided and arrangedas radially outwardly extending helically-shaped protrusions on theouter circumference of the dose tracking member 40. As shown in FIG. 21, the first keying structure 41 and the second keying structure 42 arein direct axial abutment. The first keying structure 41 comprises afirst keying feature 43 inform of a radial recess or radial gap. Alsothe second keying structure 42 comprises a second keying feature 44 inthe form of a radial recess or gap. The radially extending recesses andhence the first and the second keying features 43, 44 are configured toreceive the radially inwardly extending keying features 263, 264 of thelimiter 260.

In the configuration as shown in FIGS. 16 and 17 the keying features263, 264 protrude radially inwardly and may extend through acorrespondingly -shaped through opening or recess in the sidewall of themain housing component 14. In order to allow and to support a distallydirected axial displacement of the trigger 250 the protrusions and hencethe first and the second keying features 263, 264 at least temporallyenter the correspondingly shaped keying features 43, 44 of the first andthe second keying structures 41, 42, respectively. If properly aligned,the mutually engaging keying features 43, 44, 263, 264 allow for aradially inwardly directed deflection or movement of the first andsecond engaging sections 261, 262 of the limiter 260. A radiallyinwardly directed deflection or movement of the first and secondengaging section 261, 262, is governed and initiated by mutuallycorresponding beveled sections 267, 257 of the trigger 250 and of thelimiter 260, respectively.

In the configuration as shown in FIGS. 16 and 18 , the distal endsection 254 of the trigger 250 is in axial and beveled abutment with aradially outwardly protruding beveled section 267 of the first and ofthe second engaging sections 261, 262. The mutual abutment of thebeveled section 267 with a correspondingly shaped counterpart section257 at the distal end of the trigger 250 is shown in FIG. 18 . Since thecounterpart section 257 comprises an annular and closed shape at thedistal end of the cup-shaped trigger 250, the counterpart section 257 israther stiff. As illustrated in FIG. 18 , the outer diameter or theradial distance between the beveled sections 267 of the first and of thesecond engaging sections 261, 262 is larger than the inner or insidedistance between correspondingly shaped and oppositely located portionsof the counterpart section 257.

In this way, and as long as the first and/or the second engagingsections 261, 262 are hindered from deflecting radially inwardly adistally directed movement of the trigger 250 towards the dosedispensing position d is effectively blocked. In FIG. 18 , such ablocking configuration and hence a blocking position of the limiter 250is shown. The keying feature 263 of the first engaging section 261 is inradial abutment with the first keying structure 41 of the dose trackingmember 40. As illustrated in FIG. 16 . The same is also valid for thesecond keying feature 264 of the second engaging section 262. As thedose tracking member 40 is turned and reaches an allowable positionalstate a respective keying feature 43 will be aligned radially inwardlyto the first keying feature 263. Also, the second keying feature 264will be aligned with the second keying feature 44 of the dose trackingmember 40.

As the mutually corresponding keying features 43, 263 and 44, 264 of thedose tracking member 40 and the limiter 260 correctly align the firstand second engaging sections 261, 262 will be allowed to deflectradially inwardly under the action of the distally advancing trigger250. This radially inwardly directed motion is due to the beveled ortilted slope of the mutually engaging counterpart section 257 of thetrigger 250 and the beveled section 267 on the outside surface of thefirst and second engaging sections 261, 262, respectively.

With the radially inwardly directed deflection of the first engagingsection 261 as shown in FIG. 19 the trigger 250 is enabled to reach itsdistal dose dispensing position d as shown in FIG. 20 . In this positionthe radially inwardly extending counterpart section 257 is locateddistally from the radially outwardly extending beveled section 267 ofthe first and the second engaging sections 261 and 262 respectively.

Once the trigger 250 has reached the distal dose dispensing position das shown in FIG. 20 the radially inwardly protruding or radiallyinwardly extending counterpart section 257 of the trigger 50 is entirelylocated distally from the beveled section 267 of the limiter 260. As aconsequence, the first and second engaging sections 261, 262 and hencethe keying features 263, 264 are allowed to return into their initialposition in which the innermost portion of the keying features 263, 264of the limiter 260 are located radially outside the keying structures41, 42. In this way, a frictionless or contactless configuration of thekeying features 263, 264 with regard to the keying structures 41, 42 canbe obtained, thus allowing the dose tracking member 42 to return intoits initial configuration during the dose dispensing procedure.

As seen from the proximal end towards the distal end the beveledsections 267 of the first and the second engaging sections 261, 262 ofthe limiter 260 extend radially outwardly in distal direction. In theinitial or idle position i as shown in FIG. 18 the correspondinglybeveled counterpart section 257 of the trigger 250 is located proximallyfrom the beveled section 267. As the trigger 250 and hence thecounterpart section 257 advances in distal direction, hence downwards inFIGS. 19 and 20 . The first and the second engaging sections 261, 262experience a radially inwardly directed deflection.

This deflection is only possible if the respective keying features 263,264 are circumferentially and axially properly aligned with thecorrespondingly shaped keying features 43, 44 of the dose trackingmember 40. This is shown in more detail in FIG. 22 . There, the firstkeying feature 263 of the first engaging section 261 is at the sameaxial and the same circumferential position as the correspondinglyshaped first keying feature 43 of the dose tracking member 40. The firstkeying feature 43 is configured and shaped to receive the protrusion ofthe first keying feature 263 so as to enable and to support a radiallyinwardly directed deflection of the respective engaging section 261.

Also with the example of FIGS. 15 to 22 the pairs of mutuallycorresponding engaging features 43, 263 and 44, 260 4 simultaneouslyengage or simultaneously disengage. In this way both legs 265, 266 orboth engaging sections 261, 262 either provide an axial bearing for thedistal end section of the trigger 250 or both engaging sections 261, 262simultaneously deflect radially inwardly so as to give way for thedistally advancing trigger 250.

As it is further shown in FIGS. 16, 17 , and in FIG. 22 the elasticallydeformable legs 265, 266 are not strictly oriented in axial directionwhen in an original or unbiased state. Rather, they extend at a slightradially outwardly extending angle a with regard to the axial directionor longitudinal direction of the housing 10. In this way, and asindicated in FIG. 22 to the elongation of the legs 265, 266 is orientedat a predefined angle a outwardly from the longitudinal direction of thehousing 10 or the dose tracking member 40. The first and/or the secondleg 265, 266 may extend at a small but distinct angle a. Alternatively,the first and the second leg 265, 266 may extend substantially parallelwith respect to each other but at a predefined clearance or at apredefined radial distance from the dose tracking member 40.

In this way, there is formed and provided a radial gap or radialclearance between the keying features 263, 264 of the limiter 260 andthe keying structures 41, 42 of the dose tracking member when there isno distally directed pressure applied to the trigger 50, e.g. duringdose setting. The radially inwardly extending protrusions and hence thefirst and the second keying features 263, 264 of the limiter 260 are ina contactless configuration relative to the keying structures 41 or 42on the outside surface of the dose tracking member 40. Hence, duringdose setting and while the dose tracking member 40 is subject of arotation there is no friction between the keying features 263, 264 ofthe limiter 260 and the keying structures 41, 42 of the dose trackingmember 40. The dose tracking member 40 and hence the number sleeve 70can be subject to a helical motion relative to the housing 10 with acomparatively low degree of dynamic friction.

In FIGS. 23 to 33 another example of a limiter 360 to cooperate with adose tracking member 40 is illustrated. With this example, the injectiondevice 1 comprises a proximal end with a rotatable handle 90. There isfurther provided a trigger 50 as already described in connection withFIGS. 1 through 10 . As shown in longitudinal cross-section of FIGS. 23and 24 , the limiter 360 comprises a rim shaped or annular shapedproximal end 369 with an axial through opening 376 extending therethrough. The limiter 360 also comprises a first and axially elongatedengaging section 361 and a second axially elongated engaging section362. At an inside facing portion near a distal end of the first and thesecond engaging sections 361, 362, there are provided first and secondkeying features 363, 364, respectively.

Also here, the first engaging section 361 is formed by a first leg 365.The second engaging section 362 is formed by a second leg 366. The legs365, 366 and hence the first and the second engaging sections 361, 362are located at diametrically opposite locations with regard to thetubular shape of the dose tracking member 40 located there between.Alternative Contraryto the examples described before the limiter 360 isaxially displaceable between a distal release position r as shown inFIG. 23 and a proximal blocking position b as shown in FIG. 24 . In theblocking position b and hence when displaced proximally from the releaseposition r the limiter 360 is configured to engage with two blockingelements 370, 372. Movement of the limiter 360 is not directly driven bya movement of the trigger 50. Here, an axial movement of the limiter 360is exclusively triggered and governed by the mutual interaction betweenthe limiter 360 and the dose tracking member 40. When in a blockingconfiguration or blocking position b movement of the trigger 50 iseffectively blocked by the limiter 360.

The blocking elements 370 are located axially beneath the trigger 50.Both blocking elements 370, 372 comprise a proximal end 371, 373. In aninitial or idle configuration, the blocking elements 370, 272 extendalong the axial direction or axial elongation of the housing 10. As thelimiter 360 is shifted or displaced towards the proximally locatedblocking position b the proximal end section 369 thereof simultaneouslyengages with the blocking elements 370, 372 in such a way that theproximal ends 371, 373 thereof are moved radially outwardly.

In this way, the proximal ends 371, 373 of the blocking elements 370,372 extend outwardly and enter a free space, which is normally occupiedby the button portion 53 of the trigger when reaching the dosedispensing position d. In the blocking position b the proximal ends 371,373 of the blocking elements 370, 370 are configured to impede a furtherdistally directed advancing motion of the trigger 50. Hence, the trigger50 engages with the blocking elements 370, 372 and is hindered to reachthe dose dispensing position d.

The blocking elements 370, 372 may be integrally formed with the handle90. They may be flexibly or resiliently connected to an inner sleeve 91of the handle 90. The inner sleeve 91 is rotationally supported on thedrive sleeve 25. It may be rotationally disengaged from the drive sleeve25 to allow for a rotation of the handle 90 relative to the drive sleeve25 during dose setting as well as during dose dispensing.

The blocking elements 370, 372 may be integrally formed or may be moldedto the inner sleeve 91. The blocking elements 370, 372 comprise an axialmidsection, that is connected to an outer circumference of the innersleeve 91. The blocking elements 370, 372 are connected to the innersleeve 91 by means of a radially outwardly extending connecting link 92so that the blocking elements 370, 372 are located at a predefinedradial distance from the outer circumference of the inner sleeve 91.This allows for a pivoting or rotating motion of the blocking elements370, 372 with a pivot axis coinciding with the connecting link 92 asillustrated in FIGS. 23 and 24 .

The proximal end section 369 of the limiter 360 comprises a beveledsection 368 at an inside facing sidewall portion. The beveled section368 is in axial abutment or close to an axial abutment with the distalend 374, 375 of the blocking elements 370, 372. The beveled section 368extends radially inwardly in distal direction. As the limiter 360 ismoved from the release position as shown in FIG. 23 and towards theblocking position as shown in FIG. 24 the beveled section 368 engageswith the distal ends 374, 375 of the blocking elements 370, 372.

Consequently, the distal ends 374, 375 become subject to a radiallyinwardly directed displacement. This displacement leads to a rotation orpivoting motion of the blocking elements 370, 372, such that theirproximal ends 371, 373 move radially outwardly. The blocking elements370, 372 resiliently pivot with the connecting link 92 as a pivot axis.The pivot axis extends tangentially or circumferentially, henceperpendicular to the elongation of the housing 10.

The blocking elements 370, 372 are resiliently supported on the handle90. In the region and by means of the connecting link 92 the blockingelements 370, 372 are resiliently deformable or pivotable against arestoring force. As the limiter 360 returns into its distal releaseposition r the blocking elements 370, 372 return into their initialconfiguration as shown in FIG. 23 , in which the blocking elements 370,372 are substantially aligned in an axial direction.

Alternative to the example as shown in FIGS. 1 to 22 the limiter 360 isaxially displaceable inside the main housing component 14 between thedistally located release position r and the proximally located blockingposition b. An axial displacement of the limiter 360 is governed andconducted by mechanical interaction with the dose tracking member 40.The dose tracking member 40 comprises a tubular -shaped sleeve. The dosetracking member 40 as shown in the example of FIG. 26 is substantiallyidentical to the dose tracking member 40 as described in connection withFIGS. 1 to 6 . It is engaged with the housing 10 by means of a slottedlink 12. In the present example the dose tracking member comprises afirst keying structure 41 and a second keying structure 42 that extendparallel. Both keying structures 41, 42 comprise a helical thread on theoutside surface of the dose tracking member 40. Here, the dose trackingmember 40 also provides and constitutes a number sleeve 70.

The first keying structure 41 comprises at least a first keying feature43 in form of a recess, an axial slot or gap in the outer thread. Alsothe second keying structure 42 comprises a second keying feature 44,which is likewise configured in the form of a recess, an axial slot orgap in the respective outer thread. Contrary to the examples as shown inFIGS. 1 to 6 the keying features 43, 44 of the dose tracking member 40as shown in FIG. 26 comprise a chamfered end section 49 as shown indetail in FIG. 27 . In FIGS. 27 to 31 the distal axial direction pointsdownward and the circumferential or tangential direction of the dosetracking member 40 is aligned horizontally.

The keying features 363 and 364 of the limiter 360 are configured toengage and to interact with the correspondingly shaped keying features43, 44 of the dose tracking member 40. As shown in FIGS. 27 through 31the keying features 363, 364 comprise radially inwardly extendingprotrusions on an inside facing surface of the first leg 365 and secondleg 364, respectively. The first keying feature 363 comprises a bevelededge 367 as seen in tangential direction. The beveled edge 367 is shapedto conform with the chamfered end section 49 of the first keyingstructure 41.

In an initial configuration as shown in FIG. 27 the first keying feature363 at least partially overlaps in axial direction with the chamferedend section 49 of the first keying structure 41. In this configurationthe first keying structure 363 extends radially inwardly and into therecess, slot or gap of the first keying structure 41. As the dosetracking member 40 is subject to a rotation the beveled edge 367 of thefirst keying feature 363 slides along the correspondingly -shapedchamfered edge 49 of the first keying structure 41. As a consequence,the first keying feature 366 and hence the entire limiter 360experiences a proximally directed displacement until the entirety of thekeying features 363 is located proximally of the chamfered end section49 as shown in FIG. 29 .

In this configuration the limiter 360 has reached a blocking position b.In this configuration a distal edge of the first keying feature 363 isin axial abutment with a proximal edge of the first keying structure 41.In this configuration and due to the axial abutment of the keyingfeature 363 of the limiter 360 with the keying structure 41 of the dosetracking member 40 a distally directed displacement of the limiter 360is effectively blocked and prevented. Accordingly and due to thedisplacement of the limiter 360 towards the proximal blocking position bthe blocking elements 370, 372 have reached a respective blockingconfiguration as shown in FIG. 24 in which they effectively impede adistally directed depression of the trigger 50.

It is only when the dose tracking member 40 is dialed or rotated furtherand until another first keying structure 43′ is aligned with the firstkeying structure 363 of the limiter 360 that the limiter 360 isdisplaceable in distal direction, and downwardly in FIG. 30 . A movementof the limiter 360 in distal direction is induced by the resilientrestoring force provided by the blocking elements 370, 372. Here, thedistal ends 374, 375 exert a radially outwardly directed restoring forceonto the beveled section 368 of the proximal end 369 of the limiter 360.As soon as the first keying structure 363 is properly aligned with thefirst keying feature 43 ‘of the dose tracking member 40 the limiter 360will be pushed or will return at least into the configuration as shownin FIG. 27 . Simultaneously, also the second keying structure 364 willbe axially aligned with a corresponding second keying feature 44 ‘of thedose tracking member 40. Consequently, the limiter 360 will be pusheddistally towards and/or into the release configuration r as shown inFIG. 27 .

In the release configuration r a distally directed depression of thetrigger 50 is enabled. As it is apparent from FIGS. 32 and 33 a distallydirected depression of the trigger 50 leads to a corresponding distallyadvancing motion of the drive sleeve 25. Here, the bottom of the buttonportion 53 of the trigger 50 axially abuts against the proximal end face27 of the drive sleeve 25. Furthermore and as shown in FIGS. 23, 24, 32and 33 the drive sleeve 25 comprises two radially outwardly extendingengaging sections 24 a, 24 b.

Both engaging sections 24 a, 24 b comprise a radially outwardlyextending rim or protrusion rib. The engaging section 24 a is locateddistally compared to the position of the engaging section 24 b. Axiallybetween the two engaging sections 24 a, 24 b there is located at leastone radially inwardly extending tappet 380 protruding radially inwardlyfrom the annular shaped proximal end section 369 of the limiter 360. Thetappet 380 protrudes radially inwardly from the annular section 369 ofthe limiter 360 It is in radial engagement with the outer circumferenceof the drive sleeve 25. The tappet 380 is configured to selectivelyaxially engage with the distally located engaging section 24 a and withthe proximally located engaging section 24 b.

In the release configuration as shown in FIGS. 23 and 32 in which thefirst keying feature 363 at least partially axially overlaps and engageswith the first keying structure 41 of the dose tracking member 40 thetrigger 50 is fully depressible. As the trigger 50 is depressed anddisplaced towards the distal end 5 of the injection device 1 the drivesleeve 25 is also displaced distally until the proximally locatedengaging section 24 b axially abuts the tappet 380. This abutmentconfiguration is attained before the trigger 50 reaches the dosedispensing position d. By means of the axial engagement of the tappet380 with the engaging section 24 b the limiter 360 will be displaced andmoved in distal direction as the trigger 50 is displaced further indistal direction. This is illustrated in FIG. 33 .

Due to the axial engagement between the tappet 380 and the engagingsection 24 b the first keying structures 363 entirely traverses thefirst keying structure 43 of the first keying structure 41 of the dosetracking member 40. As the trigger 50 reaches the dose dispensingposition d the first keying structure 363 is located in its entiretydistally from the first keying structure 41. In this configuration andduring the subsequently ongoing dose dispensing procedure the dosetracking member 40 and hence the keying structure 41 may be subject to adose decreasing rotation as shown by the horizontal arrow in FIG. 31 .

When upon completion of the dose dispensing the trigger 50 is releasedit will return into its initial or idle position i as indicated in FIG.32 . Since the trigger 50 is axially engaged with the drive sleeve 25the proximally directed displacement of the trigger 50 leads to acorresponding proximally directed movement of the drive sleeve 25.Consequently, the distally located engaging section 24 a axially abutswith the tappet 380. The engaging section 24 a, and in particular aproximally facing side edge thereof axially abuts a distally facing edgeof the tappet 380. In this way, the tappet 380 and the entire limiter360 is dragged in the proximal direction under the action of theproximally returning drive sleeve 25 until the limiter 360 reaches theinitial release position r as indicated in FIG. 27 .

Even though there is shown only the interaction between a first keyingfeature 363 with a first keying structure 41 of the dose tracking member40 in the sequence of FIGS. 27 to 31 the dose tracking member 40 and thelimiter 360 are in a pairwise mechanical engagement by means of a firstpair of keying features and by means of a second pair of keyingfeatures. The second pair of keying features comprises a second keyingfeature 364 on the second engaging section 362 of the limiter 360 and asecond keying feature 44 on or intersecting the second keying structure42 of the dose tracking member 40.

Moreover, from FIGS. 32 and 33 it is apparent that there are provided atleast two radially inwardly extending tappets 380 or pins along aninside facing sidewall portion of the proximal end 369 of the limiter360. By means of several and circumferentially distributed tappets 380 arather smooth and purely axial displacement of the limiter 360 free oftilt or cant can be provided.

With the example according to FIGS. 23 through 33 it is of particularbenefit, that axial load applied to the trigger 50 is substantiallyentirely counteracted by the blocking elements 370, 372 if the injectiondevice 1 is in a blocking configuration as shown in FIG. 24 . Axial loadapplied to the trigger 50 in distal direction is transferred via theblocking elements 370, 372 towards and into the handle 90. Since thehandle 90 is axially supported by the housing 10 the axial load path inthe blocking configuration is located outside the mechanical interactionof the limiter 360 and the dose tracking member 40. Axial load acting onthe trigger 50 in the locking configuration is directly transferred viathe blocking elements 370, 372 into the handle 90 and into the housing10. The mechanical components of the dose setting mechanism 3 and themechanical components of the windup expelling mechanism 2 and theirmechanical engagement or interaction does not have to withstand axialload applied to the trigger 50 when the injection device 1 is in thelocking configuration. This is beneficial for a long-lasting andreliable operational capability of the windup expelling mechanism 2 andthe dose setting mechanism 3.

In the following some further components of the dose setting mechanism 3and of the windup expelling mechanism 2 are described exemplary withregards to the example of an injection device 1 as shown in FIGS. 1 and2 . This example is only illustrative of one injection device of aplurality of injection devices to which the concept of the dose trackingmember 40 and the limiter 60 as described herein is generallyapplicable.

The windup expelling mechanism 2 comprises the piston rod 30. The pistonrod 30 comprises a pressure piece or a bearing 31 at its distal end. Thebearing 31 is rotatably supported on a distal tip of the piston rod 30.The bearing 31 is configured to axially abut against a proximally facingend face of the bung 22 of the cartridge 20. The piston rod 30 comprisesan outer thread 32 that is threadedly engaged with correspondinglyshaped threaded nut 33 which is permanently fixed to the main housingcomponent 14.

The threaded nut 33 comprises a threaded through opening through whichthe piston rod 30 extends. A rotation of the piston rod 30 relative tothe threaded nut 33 in a dose decrementing direction leads to a distallydirected advancing motion of the piston rod 30 during a dose dispensingprocedure.

The piston rod 30 further comprises at least one or two axiallyextending grooves on its outer circumference intersecting the outerthread 32. The grooves are in permanent keyed engagement withcorrespondingly shaped radially inwardly extending protrusions of aspline nut 34. The spline nut 34 comprises radially outwardly extendingand radially deflectable clicker arms that bump over correspondingly-shaped teeth on the inside surface of the main housing component 14,thereby creating an audible dispensing click during dose dispensing.

The piston rod 30 axially extends through the hollow drive sleeve 25.The drive sleeve 25 is selectively rotationally engageable with thehandle 90. The handle 90 is axially fixed to the main housing component14. It is rotatable relative to the main housing component 14. Thehandle 90 comprises a dose dial to set or to select a dose of variablesize.

The drive sleeve 25 is snapped to a ratchet sleeve 80 that is radiallysandwiched between the dose tracking member 40 and the drive sleeve 25.The drive sleeve 25 and the ratchet sleeve 80 are axially fixed. Thedrive sleeve 25 is rotatable relative to the ratchet sleeve 80 within alimited range so as to provide a small amount of rotational play.

The mechanical energy reservoir 75 in the form of a helically woundspring is radially sandwiched between the drive sleeve 25 and theratchet sleeve 80. One axial end 76 of the mechanical energy reservoir75 is connected to an insert 95 axially and rotationally fixed to theproximal end of the main housing component 14. The other axial end 77 ofthe mechanical energy reservoir 75 is connected to the ratchet sleeve80. The insert 95 also serves as a zero-dose stop. It provides anabutment for the dose tracking member 40 when the dose tracking member40 reaches the zero-dose configuration, typically at the end of a dosedispensing procedure.

The dose tracking member 40 provides and serves as a number sleeve 70.It comprises an outer threaded section 41, 42 threadedly engaged with aninner threaded section 11 of the main housing component 14. In additionthe dose tracking member 40 is in permanent splined engagement with theratchet sleeve 80. The splined engagement of the ratchet sleeve 80 andthe dose tracking member 40 comprises an elongated groove provided onone of the dose tracking member 40 and the ratchet sleeve 80 and acorrespondingly shaped protrusion or pin located on the other one of thedose tracking member 40 and the ratchet sleeve 80. In this way the dosetracking member 40 is permanently rotationally fixed to the ratchetsleeve 80. At the same time and due to the threaded engagement with themain housing component 14 the dose tracking member 40 is subject to ahelical motion during dose setting and during dose dispensing so as toprovide a sequence of decreasing or increasing numbers in the dosagewindow 17.

Between the ratchet sleeve 80 and the spline nut 34 there is provided alocking nut 36. The locking nut 36 is rotationally locked to the mainhousing component 14 by means of external ribs engaging withcorrespondingly shaped teeth in the main housing component 14. Asindicated in FIG. 1 a ratchet arm of the ratchet sleeve 80 clicks overratchet teeth inside the locking nut 36. In this way, the ratchet sleeve80 is rotatable in a dose incrementing or dose decrementing direction indiscrete steps. The ratchet arm of the ratchet sleeve 80 is strongenough to prevent stored energy of the mechanical energy reservoir 75 todissipate in an uncontrolled way. The ratchet arm prevents the helicalspring from unwinding.

On the outer circumference and near the proximal end of the drive sleeve25 there are provided clutch teeth to engage with correspondingly -shaped clutch teeth of the handle 90. In this way and when in the idleposition i as shown in FIG. 2 the handle 90 is rotationally engaged withthe drive sleeve 25. A rotation of the handle 90 equally translates intoa respective rotation of the drive sleeve 25. Since the drive sleeve 25is rotationally engaged with the ratchet sleeve 80 also the ratchetsleeve 80 is subject to a respective rotation. The rotation of thehandle 90 in a dose incrementing direction drives the drive sleeve 26and hence the ratchet sleeve 80 in the same direction. Since the ratchetsleeve 80 is connected to one end 77 of the mechanical energy reservoir75 a rotation of the ratchet sleeve 80 further arms or biases mechanicalenergy reservoir 75.

The mechanical energy stored in the mechanical energy reservoir 75 isconstrained and stored in the windup expelling mechanism 2 because theratchet arm of the ratchet sleeve 80 is prevented from rotating in theopposite direction through its engagement with teeth provided on theinside of the locking nut 36.

There is further provided a last dose nut having external ribs thatengage grooves inside the drive sleeve 25. As the handle 90 is rotatedthe drive sleeve 25 rotates the last dose nut which climbs up outerthread 32 of the piston rod 30. When the residual amount of medicamentleft in the cartridge is less than a dose intended to be set and whenhence a last dose is selected the last dose nut engages stop features atthe proximal end of the piston rod 30. Then a further rotation of thehandle 90 in a dose incrementing direction is effectively blocked.

When canceling a dose the drive sleeve 25 is subject to an oppositelydirected rotation, hence along a dose decrementing direction. Then anddue to the limited rotational play between the drive sleeve 25 and theratchet sleeve 80 the drive sleeve 25 first rotates relative to theratchet sleeve 80, thereby compressing a biasing arm. Here, a feature ofthe drive sleeve slides over the ratchet arm of the ratchet sleevepushing the ratchet arm inwardly and weakening the ratchet between theratchet sleeve 80 and the locking nut 36. This allows a user to overcomethe ratchet and to decrease a dose during a dose setting procedure.

For dispensing of a dose the user presses on the trigger 50 in distaldirection thereby compressing the trigger spring 51. Accordingly and dueto an axial abutment of the bottom of the trigger 50 with a proximal endface 27 of the drive sleeve 25 the drive sleeve 25 is displaced indistal direction. Teeth on the drive sleeve 25 then disengage fromclutch teeth in the handle 90. In this way the handle 90 is rotationallydisengaged from the drive sleeve 25. Additionally, the locking nut 36 isurged in distal direction together with the drive sleeve 24 and theratchet sleeve 80, thereby disengaging from the teeth in the housingcomponent 14. Consequently, the locking nut 36 is then free to rotaterelative to the housing 10. The mechanical energy reservoir 75 thenreleases the stored energy and sets the locking nut 36 in rotation. Thelocking nut 36 is rotationally coupled to the spline nut 34. Therefore,the spline nut 34 is rotated in a dose decrementing direction by thelocking nut 36. Due to the keyed engagement of the spline nut 34 withthe piston rod 30 the piston rod 30 starts to rotate. Due to thethreaded engagement of the piston rod 30 with the threaded not 33 thatis fixed inside the housing component 14 the piston rod 30 is subject toa combined rotational and longitudinal motion towards the distal end 5of the injection device 1.

Since the dose tracking member 40 is permanently in keyed engagementwith the ratchet sleeve 80 numbers printed on the display portion 45 ofthe dose tracking member 70 are displayed in the dosage window 17 as adose is dialed. During the dose dispensing procedure the numbers in thedosage window 17 are displayedin a decreasing order.

Releasing of the trigger 50 prior to reach a zero-dose configurationre-engages the locking nut 36 to the housing component 14 and thedispensing procedure will be immediately stopped until the trigger 50 ispressed again.

LIST OF REFERENCE NUMBERS 1 injection device

2 expelling mechanism

3 dose setting mechanism

4 proximal end

5 Distal end

6 medicament

10 housing

11 threaded section

12 slotted link

13 cartridge holder

14 main housing component

15 outer thread

16 engaging section

17 dosage window

20 cartridge

21 barrel

22 bung

23 pierceable seal

24 a engaging section

24 b engaging section

25 drive sleeve

26 flange

27 end face

28 protrusion

29 spline feature

30 piston rod

31 bearing

32 outer thread

33 threaded nut

34 spline nut

36 locking not

40 dose tracking member

41 keying structure

42 keying structure

43 keying feature

44 keying feature

45 display portion

49 end section

50 trigger

51 trigger spring

52 strut portion

53 button portion

54 end face

55 radial protrusion

56 radial protrusion

60 limiter

61 engaging section

62 engaging section

63 keying feature

64 keying feature

65 leg

66 leg

67 proximal end face

68 protrusion

69 proximal end section

70 number sleeve

75 mechanical energy reservoir

76 axial end

77 axial end

80 ratchet sleeve

90 handle

91 inner sleeve

92 connecting link

95 insert

140 dose tracking member

141 keying structure

142 keying structure

143 keying feature

144 keying feature

145 tracking sleeve

146 engaging section

160 limiter

161 engaging section

162 engaging section

163 keying feature

164 keying feature

165 leg

166 leg

167 border

168 through opening

169 proximal end section

170 number sleeve

171 threaded section

172 display portion

173 keying structure

210 interface member

211 spline feature

212 through opening

214 splined feature

240 dose tracking member

241 keying structure

242 keying structure

243 keying feature

244 keying feature

245 display portion

250 trigger

251 button

252 proximal end face

253 sidewall

254 distal end section

255 stem

256 flange section

257 counterpart section

258 splined feature

260 limiter

261 engaging section

262 engaging section

263 keying feature

264 keying feature

265 leg

266 leg

267 beveled section

268 radial gap

360 limiter

361 engaging section

362 engaging section

363 keying feature

364 keying feature

365 leg

366 leg

367 beveled edge

368 beveled section

369 proximal end

370 blocking element

371 proximal end

372 blocking element

373 proximal end

374 distal end

375 distal end

376 through opening

380 tappet

1-15 (canceled)
 16. An injection device for expelling of a number ofpreset or user-selectable doses of a medicament, the injection devicecomprising: a housing extending along an axial direction and configuredto accommodate a cartridge containing the medicament and having a bungsealing a proximal end of the cartridge, a windup expelling mechanismcomprising a piston rod, a mechanical energy reservoir, and a trigger,wherein the trigger is movable between an idle position and a doseexpelling position relative to the housing and configured to, when movedinto the dose expelling position, release energy from the mechanicalenergy reservoir to the piston rod thereby axially driving the pistonrod relative to the housing to urge against the bung, a dose settingmechanism comprising a handle for rotationally selecting a dose and/orfor arming the windup expelling mechanism, a dose tracking member, and adriver, wherein the dose tracking member is rotatable relative to thehousing within a range of positional states and operatively connectableto the handle for tracking a rotation thereof, and wherein the driver isaxially displaceable between a dose setting position and a dosedispensing position, wherein when in the dose dispensing position, thedriver is rotationally locked to the piston rod and is rotationallydisengaged from the handle, and w herein when in the dose settingposition, the driver is rotationally disengaged from the piston rod andis rotationally locked to the handle.
 17. The injection device accordingto claim 16, wherein the handle is rotatable relative to the housing forsetting of the dose of the medicament. member is rotatable in a doseincrementing direction against the action of the helical driving spring.26. The injection device according to claim 16, further comprising: afirst clutch operably engageable with the handle and with the driver,and a second clutch operably engageable with the driver and the pistonrod, wherein when the driver is in the dose setting position the firstclutch is closed and the second clutch is open to transfer a rotation ofthe handle into a rotation of the driver.
 27. The injection deviceaccording to claim 26, wherein when the driver is in the dose dispensingposition, the first clutch is open and the second clutch is closed torotationally lock the driver to the piston rod and to rotate the driverunder the action of the mechanical energy reservoir.
 28. The injectiondevice according to claim 16, wherein the dose setting mechanismcomprises a limiter which is operationally engageable with the dosetracking member and the trigger for blocking actuation of the triggerwhen the dose tracking member is in one of a number of predeterminedsections of the range of positional states.
 29. The injection deviceaccording to claim 28, wherein the limiter is movable relative to thedose tracking member.
 30. The injection device according to claim 16,further comprising a cartridge filled with the medicament and arrangedinside the housing.
 31. An injection device for expelling of a number ofpreset or user-selectable doses of a medicament, the injection devicecomprising: a housing extending along an axial direction and configuredto accommodate a cartridge containing the medicament and having a bungsealing a proximal end of the cartridge. a windup expelling mechanismcomprising a piston rod, a mechanical energy reservoir and a trigger,wherein the trigger is movable between an idle position and a doseexpelling position relative to the housing and configured to, when movedinto the dose expelling position, release energy from the mechanicalenergy reservoir to the piston rod thereby axially driving the pistonrod relative to the housing in order to urge against the bung, a dosesetting mechanism comprising a handle for rotationally selecting a doseand/or for arming the windup expelling mechanism, a dose trackingmember, wherein the dose tracking member is rotatable relative to thehousing within a range of positional states and is operativelyconnectable to the handle for tracking a rotation thereof, and whereinthe mechanical energy reservoir comprises a helical driving springcomprising a first end connected to the housing and comprising a secondend connected to the dose tracking member, wherein the dose trackingmember is rotatable in a dose incrementing direction against the actionof the helical driving spring.
 32. The injection device according toclaim 31, wherein in a dose dispensing mode of the windup expellingmechanism the dose tracking member is rotated in a dose decrementingdirection under the action of the helical driving spring.
 33. Theinjection device according to claim 31, wherein the dose tracking memberis a number sleeve comprising a helical shaped sequence of doseindicating numbers on an outer circumference.
 34. The injection deviceaccording to claim 31, wherein the dose setting mechanism comprises alimiter which is operationally engageable with the dose tracking memberand the trigger for blocking actuation of the trigger when the dosetracking member is in one of a number of predetermined sections of therange of positional states.
 35. The injection device according to claim31, further comprising a cartridge filled with the medicament andarranged inside the housing.